You searched for subject:(Optical communications).
Showing records 1 – 30 of
453 total matches.
◁ [1] [2] [3] [4] [5] … [16] ▶
University of Johannesburg
1.
Zhu, Yinian.
Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2190 
► D.Phil.
This dissertation deals with the fabrication, characterisation, and applications of long-period gratings in optical fibre communications and sensing systems. The aim of this project…
(more)
▼ D.Phil.
This dissertation deals with the fabrication, characterisation, and applications of long-period gratings in optical fibre communications and sensing systems. The aim of this project is to assess long-period gratings as media for active or passive fibre devices, particularly as components for the telecommunications industry. A review of the properties and characteristics of fibre gratings associated with the photosensitivity of germanosilicate fibres is provided, which includes a theoretical analysis of the principles of operation for short-period gratings (fibre Bragg gratings) and long-period gratings. The simulations of the spectral response from these two types of gratings are also presented. A number of long-period grating fabrication methods and techniques, which were reported by some researchers, are reviewed. In this project, the normal long-period gratings and phase-shifted long-period gratings are fabricated by using a line-narrowed KrF excimer laser combined with the metal amplitude mask technique. The metal mask is made of a stainless steel sheet, and the slot width (periodicity) is processed by using high quality photographic tooling. Three normal long-period gratings with different periodicities and one phase-shifted long-period grating can be manufactured simultaneously because there are four metal masks imprinted in one inexpensive stainless steel sheet. The mass-production of long-period gratings becomes possible, and the number of gratings that can be written is limited only by the excimer laser beam or metal mask dimension orthogonal to the fibre axis. The fibres that are used in our experiments are photosensitive optical fibres (PS1500). Long-period gratings can be written directly into these fibres without hydrogenation. Two types of long-period grating devices are investigated and developed for applications in dense wavelength division multiplexing (DWDM)networks: erbium-doped fibre amplifier (EDFA) gain-flattening filters and wavelength-tuneable add/drop multiplexers. Firstly, the transmission characteristics of phase-shifted long-period gratings are simulated theoretically by a combination of the coupled-mode theory and the fundamental-matrix method. It is suggested that a phase-shifted long-period grating device cascaded with another normal long-period grating can be used to flatten the gain spectrum of an EDFA containing three gain peaks. The experimental results show that a broad amplifier with peak-to-peak variations of less than 0.7 dB over 36 nm from 1526 to 1562 nm, which covers the entire C-band of the EDFA, can be realized practically. Next, a wavelength-tuneable add/drop multiplexer is designed and configured. In this device, four identical long-period gratings are assembled on piezoelectric ceramic fibre stretchers. The modelling of the device predicts that 50 ITU DWDM-channel signals could be selected in the wavelength range from 1526.25 to 1563.75 nm with 0.75 nm channel spacing and the cross-talk is less than –39 dB while the total insertion loss is about 0.24 dB. There…
Subjects/Keywords: Optical communications; Optical fiber detectors
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhu, Y. (2009). Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2190
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhu, Yinian. “Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems.” 2009. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/2190.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhu, Yinian. “Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems.” 2009. Web. 16 Jan 2021.
Vancouver:
Zhu Y. Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/2190.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhu Y. Fabrication of long-period gratings and their applications in optical fibre communications and sensing systems. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2190
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Johannesburg
2.
Menyennett, Calvin.
Constrained sequences and codes for binary asymmetrical optical channels.
Degree: 2014, University of Johannesburg
URL: http://hdl.handle.net/10210/9772
► M.Ing. (Electrical and Electronic Engineering)
During the past decade the optical disc has become increasingly popular. Write-once optical recording systems will mainly be used in…
(more)
▼ M.Ing. (Electrical and Electronic Engineering)
During the past decade the optical disc has become increasingly popular. Write-once optical recording systems will mainly be used in data storage systems in which archival aspects or mass storage requirements prevail. In write-once optical data storage one is faced with an asymmetry between marks and non-marks due to a practical lower limit of the mark size. In some optical fibre communications there is also an asymmetry present in injection lasers and it may be feasible to use asymmetrical codes. In this study information theoretical methods are used to find values of channel capacity for sequences complying with binary asymmetrical runlength constraints. Different coding methods are used to construct encoders and decoders for generating and decoding these sequences with high values of efficiency. The power spectra of maxentropic binary asymmetrical runlength limited sequences complying with different runlength constraints are also investigated.
Subjects/Keywords: Optical communications; Optical disks
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Menyennett, C. (2014). Constrained sequences and codes for binary asymmetrical optical channels. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/9772
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Menyennett, Calvin. “Constrained sequences and codes for binary asymmetrical optical channels.” 2014. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/9772.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Menyennett, Calvin. “Constrained sequences and codes for binary asymmetrical optical channels.” 2014. Web. 16 Jan 2021.
Vancouver:
Menyennett C. Constrained sequences and codes for binary asymmetrical optical channels. [Internet] [Thesis]. University of Johannesburg; 2014. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/9772.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Menyennett C. Constrained sequences and codes for binary asymmetrical optical channels. [Thesis]. University of Johannesburg; 2014. Available from: http://hdl.handle.net/10210/9772
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Oregon State University
3.
Chu, Yu-Jung.
Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells.
Degree: MS, Electrical and Computer Engineering, 2016, Oregon State University
URL: http://hdl.handle.net/1957/59344
► As the price of broadband access service becomes more affordable, the number of homes with WiFi and public WiFi hotspots in the US are projected…
(more)
▼ As the price of broadband access service becomes more affordable, the number of
homes with WiFi and public WiFi hotspots in the US are projected to increase significantly in the next few years. However, limited capacity of existing WiFi networks fail to
provide adequate bandwidth for densely populated areas. Therefore, in this thesis, we
describe WiFO, a novel communication system that integrates free space
optical communication and WiFi technologies to provide an order of magnitude improvement in
wireless capacity. Specifically, the thesis will focus on the mobility protocols and novel
modulation and channel estimation techniques in order to provide high bit rates and
large coverage.
Advisors/Committee Members: Nguyen, Thinh (advisor), Bose, Bella (committee member).
Subjects/Keywords: WIFO; Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chu, Y. (2016). Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/59344
Chicago Manual of Style (16th Edition):
Chu, Yu-Jung. “Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells.” 2016. Masters Thesis, Oregon State University. Accessed January 16, 2021.
http://hdl.handle.net/1957/59344.
MLA Handbook (7th Edition):
Chu, Yu-Jung. “Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells.” 2016. Web. 16 Jan 2021.
Vancouver:
Chu Y. Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells. [Internet] [Masters thesis]. Oregon State University; 2016. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1957/59344.
Council of Science Editors:
Chu Y. Mobility Protocol, Channel Estimation and Modulation Techniques for Hybrid WiFi-FSO (WiFO) WLAN of Femtocells. [Masters Thesis]. Oregon State University; 2016. Available from: http://hdl.handle.net/1957/59344
University of Johannesburg
4.
Nhlapo, Thabiso J.
Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2176
► M.Ing.
This thesis is about the gain equalization of erbium doped fibre amplifiers (EDFA), which is a key technology for enabling wavelength-division multiplexed (WDM) optical…
(more)
▼ M.Ing.
This thesis is about the gain equalization of erbium doped fibre amplifiers (EDFA), which is a key technology for enabling wavelength-division multiplexed (WDM) optical communication systems. In order to flatten dynamically the EDFA gain spectrum, a tuneable long-period grating filter was demonstrated. Long-period gratings were fabricated by using a KrF excimer laser combined with the metal amplitude mask technique. The transmission spectrum characteristic of the long- period grating was simulated theoretically by the coupled-mode theory. The coupling between the core and cladding modes of the long-period grating was investigated both experimentally and theoretically. The EDFA was constructed by using the forward pumping configuration consisting of pump laser source, WDM couplers, an optical isolator, and the erbium-doped fibre. The EDFA was characterized theoretically and experimentally for WDM applications. The tuneable long-period grating filter design is based on the tuneable coupler that uses the Mach-Zehnder interferometer configuration. The tuneable filter was demonstrated by equalizing the EDFA gain spectrum and the amplified spontaneous emission (ASE) source. The main advantage of this filter compared to other optical filters is its tuneability of the attenuation over a wide range of pump power.
Subjects/Keywords: Optical amplifiers; Optical fibers; Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Nhlapo, T. J. (2009). Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2176
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nhlapo, Thabiso J. “Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings.” 2009. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/2176.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nhlapo, Thabiso J. “Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings.” 2009. Web. 16 Jan 2021.
Vancouver:
Nhlapo TJ. Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/2176.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nhlapo TJ. Gain equalization of erbium doped fibre amplifiers with tuneable long-period gratings. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2176
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Johannesburg
5.
Botha, Roelene.
Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2153
► M.Ing.
Long distance optical communication systems experience a large degree of attenuation due to fibre losses, necessitating signal amplification. Erbium Doped Fibre Amplifiers (EDFAs) have…
(more)
▼ M.Ing.
Long distance optical communication systems experience a large degree of attenuation due to fibre losses, necessitating signal amplification. Erbium Doped Fibre Amplifiers (EDFAs) have found widespread use as all-fibre optical amplifiers, but exhibit unequal amplification of different wavelengths. Since the gain spectrum is signal-power and pump-power dependent, each EDFA spectrum may differ considerably, and a tuneable gain equalizer is required. A tuneable long-period grating (LPG) can be implemented as a gain equalizer for EDFAs. This dissertation deals with the design of an integrated optic version of the tuneable equalizing filter. The various components of which the device comprises, including optical couplers, Mach-Zehnder interferometers and an LPG, are investigated. The integrated optics designs of these components are then done using the BeamPROP software package. The use and optical properties of germania-doped silica as photosensitive waveguide material is studied. The production of the films for the gain equalizer, using electron-cyclotron resonance plasma-enhanced chemical vapour deposition, is discussed. Characterization of these films was carried out using spectroscopic ellipsometry and infrared spectroscopy. The optical constants, thickness, germania content and hydroxyl absorption was calculated using these measurements.
Subjects/Keywords: Optical amplifiers; Optical fibers; Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Botha, R. (2009). Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2153
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Botha, Roelene. “Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers.” 2009. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/2153.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Botha, Roelene. “Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers.” 2009. Web. 16 Jan 2021.
Vancouver:
Botha R. Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/2153.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Botha R. Towards an integrated optic tuneable gain equalizer for erbium-doped fibre amplifiers. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2153
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Oregon State University
6.
Trullinger, Von.
Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments.
Degree: MS, Electrical and Computer Engineering, 2004, Oregon State University
URL: http://hdl.handle.net/1957/11503
► The desire to apply short-range wireless communication systems to telemetry sensor networks in a metal-enclosed chamber has prompted this study. This thesis will discuss the…
(more)
▼ The desire to apply short-range wireless communication systems to telemetry sensor
networks in a metal-enclosed chamber has prompted this study. This thesis will discuss
the design of an infrared (IR) communication system for a wireless low-power, low-data-
rate sensor network in a metal enclosure. This design requires an in-depth understanding
of the environment and how IR will propagate in it. The metal enclosure o®ers the
advantage of little background (ambient) lighting noise, which is the main noise source
in IR communication. Also, due to the small dimensions of this enclosure, the non-line-of-
sight (NLOS) communication will take advantage of the re°ected paths o® the walls. To
improve system performance in this di®use NLOS communication environment, angular
diversity will be employed and tested. It will be shown that these di®use re°ections are
an advantage at low data rates (< 1Mbps), but then become a hindrance at higher data
rates (> 10Mbps) due to inter-symbol interference (ISI) caused by channel excess delay.
All measurement results, including bit error rate (BER) versus transmitted power, will
be presented.
Advisors/Committee Members: Liu, Huaping (advisor), Plant, Tom (committee member).
Subjects/Keywords: Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Trullinger, V. (2004). Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/11503
Chicago Manual of Style (16th Edition):
Trullinger, Von. “Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments.” 2004. Masters Thesis, Oregon State University. Accessed January 16, 2021.
http://hdl.handle.net/1957/11503.
MLA Handbook (7th Edition):
Trullinger, Von. “Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments.” 2004. Web. 16 Jan 2021.
Vancouver:
Trullinger V. Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments. [Internet] [Masters thesis]. Oregon State University; 2004. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1957/11503.
Council of Science Editors:
Trullinger V. Physical layer design of a robust low-power low-complexity optical wireless sensor system with angular diversity for metal-enclosed environments. [Masters Thesis]. Oregon State University; 2004. Available from: http://hdl.handle.net/1957/11503
Nelson Mandela Metropolitan University
7.
Ireeta, Winston Tumps.
Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats.
Degree: Faculty of Science, 2010, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/1478
► The topic of this thesis is aerial optical fibres in telecommunication systems: state of polarization (SOP) and polarization mode dispersion (PMD) monitoring and tolerance of…
(more)
▼ The topic of this thesis is aerial
optical fibres in telecommunication systems: state of polarization (SOP) and polarization mode dispersion (PMD) monitoring and tolerance of modulation formats. Errors in
optical fibre telecommunication systems are introduced when these polarization effects (SOP and PMD) change. These changes are so intense especially in aerial
optical fibres. Part of the backbone of South Africa’s national grid includes long distances of aerial
optical fibre between transmission exchange stations. The work in this thesis can be divided into three parts which all deal with the major aspects of PMD in deployed aerial
optical fibres: characterization, environmental effects plus other perturbations, and tolerance of different modulation formats. In our work, SOP and PMD field measurements revealed that they both fluctuate more rapidly in deployed aerial
optical fibres especially on windy and hot days. The SOP and PMD changes in the aerial
optical fibres showed a significant correlation with these environmental parameters. SOP and PMD are stochastic in nature due to changes in the properties of the
optical fibres and its positions because of both intrinsic and extrinsic perturbations. In our work, with only 184 PMD values measured and obtained by use of the FTB-5700 single-ended dispersion analyzer, the predicted theoretical Gaussian fit was obtained with a mean of 0.47 ps and standard deviation of 0.08 ps. This small standard deviation was justification for its robustness and accuracy. The statistical distributions for first-order polarization mode dispersion (FO-PMD) and second-order polarization mode dispersion (SO-PMD) for the first time were experimentally confirmed when measured using the FTB-5700 single-ended dispersion analyzer instrument for deployed aerial
optical fibres. We were also able to determine the time scale over which to compensate FO-PMD in deployed aerial fibres using the directional time drift autocorrelation function method. It is slightly higher than 390 s for SOP measurements made on a particular windy and hot day. This is due to the fact that the changes of the PMD vector are known to be slower than the SOP changes. vi We also investigated the theoretical statistical distribution that corresponds to output SOP variations. The SOP variations can either be with wavelength (for buried fibre) or with time (for aerial fibre). Our results showed that the statistics of the relative SOP changes approached the distribution proposed by Foschini et al. (2000). Advanced
optical modulation formats have become a key ingredient in the design of modern state-of-the-art wavelength-division-multiplexed (WDM)
optical transmission systems. In our work, we investigated which of these advanced modulation formats is best suited for the South African network especially on systems that have links of aerial
optical fibres. Keywords: aerial
optical fibre, polarization mode dispersion (PMD), principal states of polarization (PSP), state of polarization (SOP), first-order PMD, second-order PMD
Advisors/Committee Members: Leitch, Andrew W R Prof.
Subjects/Keywords: Optical communications; Fiber optics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ireeta, W. T. (2010). Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/1478
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ireeta, Winston Tumps. “Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats.” 2010. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/1478.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ireeta, Winston Tumps. “Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats.” 2010. Web. 16 Jan 2021.
Vancouver:
Ireeta WT. Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2010. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/1478.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ireeta WT. Aerial optical fibres in telecommunication systems : SOP and PMD monitoring, and tolerance of modulation formats. [Thesis]. Nelson Mandela Metropolitan University; 2010. Available from: http://hdl.handle.net/10948/1478
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Johannesburg
8.
Van Zyl, Hendrik Gideon.
Modelling of integrated optic components for lightwave communications systems using the beam propagation method.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2193
► M.Ing.
All-optical networks, although highly promising, have a long way to go before they will replace existing optical networks such as SONET. The development of…
(more)
▼ M.Ing.
All-optical networks, although highly promising, have a long way to go before they will replace existing optical networks such as SONET. The development of the all-optical networks relies on the components market to supply reliable and integrated components to facilitate filtering and management in the optical domain. Planar lightwave circuits (PLCs) and photonic integrated circuits (PICs) provide the answer, with the potential of integrating various functions on a single substrate. The design of lightwave circuits starts with the design and testing of a waveguide. Once this manufactured waveguide exhibits the right characteristics and is proved to be reproducible, it can be used in the design of components. In industry, this design is done by utilizing the beam propagation method (BPM). In order to design useful circuits, the simulation results of simple structures should be compared with experimental results to check their sensitivity to certain parameters. Once the relationship between manufactured and simulated components is understood, the design of components can commence with confidence. In this thesis, BPM simulation results are compared with a reported manufactured waveguide, and then used to design various components used for filtering purposes in dense wavelength division multiplexed (DWDM) systems. Designs for the couplers that serve as building blocks for the filters are discussed, and a novel technique of design downscaling is presented for bi-directional couplers. The filters under investigation are all moving average filters, namely Mach-Zehnder lattice filters, and the highly integrated arrayed waveguide gratings (AWGs). Applications for both these filters are presented.
Subjects/Keywords: Optical communications; Wave guides
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Van Zyl, H. G. (2009). Modelling of integrated optic components for lightwave communications systems using the beam propagation method. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2193
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Van Zyl, Hendrik Gideon. “Modelling of integrated optic components for lightwave communications systems using the beam propagation method.” 2009. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/2193.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Van Zyl, Hendrik Gideon. “Modelling of integrated optic components for lightwave communications systems using the beam propagation method.” 2009. Web. 16 Jan 2021.
Vancouver:
Van Zyl HG. Modelling of integrated optic components for lightwave communications systems using the beam propagation method. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/2193.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Van Zyl HG. Modelling of integrated optic components for lightwave communications systems using the beam propagation method. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2193
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
9.
Jakborvornphan, Siriaksorn.
The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications.
Degree: PhD, 2017, University of Sussex
URL: http://sro.sussex.ac.uk/id/eprint/72333/
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731246
► Nowadays we are living in a well-developed technological world, supporting new services and networks with vast amounts of data streams that are being pushed through…
(more)
▼ Nowadays we are living in a well-developed technological world, supporting new services and networks with vast amounts of data streams that are being pushed through fibre optic communications systems. Thus the use of optical fibres as a transmission medium is being progressively increased for deployment in ever-wider fields. A significant increasing demand of global social information in modern communication is leading to an exponentially increasing demand for high transmission carrying capacity via fibre optical network systems. This drives towards a higher information carrying capacity than the standard systems can handle. To meet the higher bandwidth requirements with a higher capacity per cross sectional area of the fibre for future communications, maximising the density of the channels is seen as an effective solution, accomplished by simultaneously propagating the individual channels within the same fibre. A new multiplexing technique, spatial division multiplexing (SDM) based on a multi-core fibre (MCF) and a multi-mode fibre (MMF), has proved it is possible to overcome the current limitation of the carrying capacity. Our greatest concern in this research is to overcome the limited transmission capacity of current existing optical fibre systems and to progressively increase the bandwidth capacity with a simple and cost effective approach. This can be accomplished by transmitting a multiplicity of channels down a single graded-index fibre (GI-MMF) with a large core diameter. This would allow a significant increase communication bandwidths for a range of short haul communications. The proposed method exploits the phenomenon of self-imaging in the GI fibre due to the interference between the excited modes which leads to the reproduction of the original beam profile periodically along the distance of propagation. This allows the maintainance of crosstalk levels between the plurality of communication channels lower than -25 dB, and also ensures a reduction of optical losses in the perturbed-tolerance fibre for short-reach networks. We observe that crosstalk levels of nearly -30 dB can be achieved for eight spatially independent transmission channels in a GI fibre of 200 μm diameter with a well separated angle of a 45° spacing distance between adjacent channels, and with an optimum distance of 60 μm from the centre of the structure. In addition, the key studies in this work have emphasised the theoretical studies in the perspective of the fractional Fourier transform (FRT), a generalisation of the Fourier transform, and the formation of reproductions of the incident arbitrary beam profiles, defined in term of Gaussian beams with an equivalent beam diameter of 10 μm at their corresponding self-imaging distance. It was found that the launched beams simultaneously propagate and re-arranging themselves periodically at the self-imaging planes along the length of the simulated commercially available fibres and the proposed large core GI-MMF, structured with 200/400 μm (core/cladding) diameters with a numerical aperture of…
Subjects/Keywords: 620; TK5103.59 Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jakborvornphan, S. (2017). The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications. (Doctoral Dissertation). University of Sussex. Retrieved from http://sro.sussex.ac.uk/id/eprint/72333/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731246
Chicago Manual of Style (16th Edition):
Jakborvornphan, Siriaksorn. “The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications.” 2017. Doctoral Dissertation, University of Sussex. Accessed January 16, 2021.
http://sro.sussex.ac.uk/id/eprint/72333/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731246.
MLA Handbook (7th Edition):
Jakborvornphan, Siriaksorn. “The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications.” 2017. Web. 16 Jan 2021.
Vancouver:
Jakborvornphan S. The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications. [Internet] [Doctoral dissertation]. University of Sussex; 2017. [cited 2021 Jan 16].
Available from: http://sro.sussex.ac.uk/id/eprint/72333/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731246.
Council of Science Editors:
Jakborvornphan S. The use of multiple channels in graded index fibre to increase bandwidth capacity in optical fibre communications. [Doctoral Dissertation]. University of Sussex; 2017. Available from: http://sro.sussex.ac.uk/id/eprint/72333/ ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.731246
University of Southern California
10.
Huang, Hao.
Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams.
Degree: PhD, Electrical Engineering, 2017, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/529422/rec/4285
► As a fundamental property of light, orbital angular momentum (OAM) can be carried by helically phased laser beams. A light beam carrying OAM could have…
(more)
▼ As a fundamental property of light, orbital angular
momentum (OAM) can be carried by helically phased laser beams. A
light beam carrying OAM could have different azimuthal states. Each
state is usually identified by an integer l indicating that phase
twisting rate. Similar to any orthogonal mode groups, coaxially
propagating OAM beams with different states are orthogonal due to
the helical phase structure. The orthogonality of OAM beams allows
the multiplexing/demultiplexing of multiple data channels in a
single data link, in which each channel is identified by a
different OAM state. OAM multiplexing shows potential to enhance
the capacity and spectral efficiency of data transmission systems.
❧ In this dissertation, we briefly discussed the background of OAM,
and the applications of OAM for
optical communications. In the
first three chapters, we focus on the system level demonstrations
using OAM multiplexing, including a free-space data link with a
capacity of 100.8 Tbit/s and an efficient OAM demultiplexing
technique that can further reduce the crosstalk of adjacent OAM
channels. One of the challenges of free space OAM communication is
the atmospheric turbulence. In chapter 4 and 5, we demonstrated a
method to measure the wavefront of OAM beams, and a potential
approach to mitigate the channel crosstalk caused by atmospheric
turbulence. An advanced communication system is not just point
–to-point static data transmission, but also requires
reconfigurability. Basic function elements in an OAM multiplexed
system, including a reconfigurable add/drop multiplexer and tunable
mode filter is demonstrated in chapter 6 and 7, respectively.
Waveguides and modulators are critical for
optical communications.
We simulated the performance of a low-loss hollow-core waveguide
for analog signal transmission, and characterized a 100-GHz EO
polymer modulator using broadband data modulation. In the last
section, we described a subsystem in which subchannels of a 16-QAM
signal can be erased or updated optically.
Advisors/Committee Members: Willner, Alan E. (Committee Chair).
Subjects/Keywords: optical communications; vortex beam
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Huang, H. (2017). Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/529422/rec/4285
Chicago Manual of Style (16th Edition):
Huang, Hao. “Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams.” 2017. Doctoral Dissertation, University of Southern California. Accessed January 16, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/529422/rec/4285.
MLA Handbook (7th Edition):
Huang, Hao. “Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams.” 2017. Web. 16 Jan 2021.
Vancouver:
Huang H. Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams. [Internet] [Doctoral dissertation]. University of Southern California; 2017. [cited 2021 Jan 16].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/529422/rec/4285.
Council of Science Editors:
Huang H. Multiplexing techniques and reconfigurable networking
functions for optical communications using orbital angular momentum
beams. [Doctoral Dissertation]. University of Southern California; 2017. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/529422/rec/4285
University of Oklahoma
11.
Zhou, Dayong.
WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION.
Degree: PhD, 2013, University of Oklahoma
URL: http://hdl.handle.net/11244/318748
► Pointing, acquisition and tracking of a free-space optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence…
(more)
▼ Pointing, acquisition and tracking of a free-space
optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence requires a different approach than traditional free-space
optical transceivers. A recent fiber-bundle approach for beam steering at the transmitter was investigated to provide continuous beam coverage at the receiver without the application of mechanical devices. Utilizing multiple fibers-lenses sets at the receiver was also proposed to enhance the tolerance of
optical link misalignment. In this work, both laboratory experiments and software simulation were implemented to evaluate the
optical link performance for different fiber-bundle-based transceiver setups as the link parameters were varied. The performance was evaluated in terms of the coverage area at the receiver, which is a measure of misalignment tolerance and is dependent not only on wavelength but on other key parameters such as link length, transmitted power, the pattern of transmitters, beam divergence, and the receiver construction. The results showed that fiber-bindle-based transceivers reveal significant potential to maximize the up time of the link, and the results also provide guidance on the further development of the overall system. To incorporate the proposed transceiver designs, an alignment control system was developed and evaluated as well. The laboratory results show that the
optical control system successfully recovered and maintained the link while the receiver was in motion and the signal coverage at the target area was enhanced significantly.
Advisors/Committee Members: Refai, Hazem H.||LoPresti, Peter G. (advisor).
Subjects/Keywords: Optical communications; Wireless communication systems
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhou, D. (2013). WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/318748
Chicago Manual of Style (16th Edition):
Zhou, Dayong. “WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION.” 2013. Doctoral Dissertation, University of Oklahoma. Accessed January 16, 2021.
http://hdl.handle.net/11244/318748.
MLA Handbook (7th Edition):
Zhou, Dayong. “WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION.” 2013. Web. 16 Jan 2021.
Vancouver:
Zhou D. WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION. [Internet] [Doctoral dissertation]. University of Oklahoma; 2013. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11244/318748.
Council of Science Editors:
Zhou D. WIRELESS OPTICAL TRANSCEIVER DESIGN, LINK ANALISYS AND ALIGNMENT CONTROL FOR MOBILE COMMUNICATION. [Doctoral Dissertation]. University of Oklahoma; 2013. Available from: http://hdl.handle.net/11244/318748
University of Oklahoma
12.
MacDonald, Gregory.
DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS.
Degree: PhD, 2012, University of Oklahoma
URL: http://hdl.handle.net/11244/320287
► The problem of detecting activity associated with the placement of an optical tap is herein approached as a supervised machine learning anomaly identification task. The…
(more)
▼ The problem of detecting activity associated with the placement of an
optical tap is herein approached as a supervised machine learning anomaly identification task. The inputs include raw polarization measurements along with additional features derived from various visualizations of the raw data (the inputs are collectively referred to as "features"). Extreme Value Theory (EVT) is proposed as a means of characterizing normal polarization fluctuations in
optical fiber. New uses (as anomaly detectors) are proposed for some long-time statistics (Ripley\'s K function, its variant the L function, and the Hopkins statistic). These metrics are shown to have good discriminating qualities when identifying anomalous polarization measurements. The metrics have such good performance only simple algorithms are necessary for identifying modifications to fiber geometry.
Advisors/Committee Members: Sluss, James (advisor).
Subjects/Keywords: Eavesdropping; Fiber optics; Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
MacDonald, G. (2012). DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/320287
Chicago Manual of Style (16th Edition):
MacDonald, Gregory. “DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS.” 2012. Doctoral Dissertation, University of Oklahoma. Accessed January 16, 2021.
http://hdl.handle.net/11244/320287.
MLA Handbook (7th Edition):
MacDonald, Gregory. “DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS.” 2012. Web. 16 Jan 2021.
Vancouver:
MacDonald G. DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2012. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11244/320287.
Council of Science Editors:
MacDonald G. DETECTING EAVESDROPPING ACTIVITY IN FIBER OPTIC NETWORKS. [Doctoral Dissertation]. University of Oklahoma; 2012. Available from: http://hdl.handle.net/11244/320287
University of Johannesburg
13.
Kritzinger, Ronnie.
Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser.
Degree: 2012, University of Johannesburg
URL: http://hdl.handle.net/10210/6675
► M.Ing.
The development of fibre optic technology as we know it today, has taken a giant leap forward since the introduction of Internet technology and…
(more)
▼ M.Ing.
The development of fibre optic technology as we know it today, has taken a giant leap forward since the introduction of Internet technology and other telecommunication devices. More recently, the need exists to retrieve and send huge amounts of data fast and efficiently by using fibre optic cable in computer networks, without the need of expensive equipment. Due to the large amounts of data (like video and audio) that has to be sent and received across a computer network at large distances, this dissertation is primarily concerned with the design and manufacturing of low-loss uniform long period fibre gratings for the realization of future optical add/drop multiplexers. An azimuthally symmetric manufacturing method is implemented using several optical components and devices. Several electronic devices are connected to a Mannesmann Rexroth ECODRIVE03 drive controller unit, and a computer control program was written in VISUAL BASIC 6.0 to control these devices during the manufacturing of these unique LPGs. A number of theories and numerical methods such as the coupled-mode theory and the transfer matrix method are applied in the analysis, modelling, and simulation of short/long-period fibre gratings. Simulation results were obtained in MATLAB 6.5 and the code was written in such a way that the end user could simulate any short/long-period grating and obtain the necessary results such as the transmission spectra, time delay and dispersion for uniform fibre gratings. These simulations obtained were a good indication on how the experimental results should look after manufacturing the unique symmetric LPGs.
Subjects/Keywords: Optical communications; Optical fiber detectors; Fiber optics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kritzinger, R. (2012). Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/6675
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kritzinger, Ronnie. “Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser.” 2012. Thesis, University of Johannesburg. Accessed January 16, 2021.
http://hdl.handle.net/10210/6675.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kritzinger, Ronnie. “Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser.” 2012. Web. 16 Jan 2021.
Vancouver:
Kritzinger R. Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser. [Internet] [Thesis]. University of Johannesburg; 2012. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10210/6675.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kritzinger R. Manufacturing of azimuthally symmetric long-period fibre gratings using a CO2 laser. [Thesis]. University of Johannesburg; 2012. Available from: http://hdl.handle.net/10210/6675
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Melbourne
14.
WANG, KE.
Optical wireless technologies for high-speed indoor communications and interconnects.
Degree: 2013, University of Melbourne
URL: http://hdl.handle.net/11343/38706
► Broadband access networks have been widely deployed using passive optical network (PON) technologies and high-speed connectivity (up to Gbps range) can be provided to the…
(more)
▼ Broadband access networks have been widely deployed using passive optical network (PON) technologies and high-speed connectivity (up to Gbps range) can be provided to the “doorstep” of users’ premises. Furthermore, new services and portable consumer electronic platforms begin to demand more bandwidth to deliver entertainment and business, such as the high-definition (HD) video streaming, the exchange of large data files between the users and high-performance servers, and the 3D television. Consequently even higher speed is in high demand for the in-building or indoor wireless personal area networks (PANs). The optical wireless technology is a promising solution to provide broadband wireless connectivity in PANs, mainly due to the availability of huge unregulated bandwidth, the immunity to electro-magnetic wave (EMW), and the security at physical layer since the optical signal cannot penetrate walls and it is difficult to intercept the link.
In this thesis, a novel high-speed optical wireless communication system for personal areas incorporating limited mobility with the localization function is proposed. A full-duplex system with 12.5 Gbps down-link and 500 Mbps up-link is experimentally demonstrated for the first time and the trade-off between the achievable bit rate and maximum error-free (bit-error-rate [BER] < 10-9) beam footprint is investigated. Furthermore, a theoretical model allowing the major limiting factor background light in the proposed system to be analyzed is formulated and its feasibility is confirmed with verification experiments. In addition, the capability of using the proposed system to realize indoor localization function is also demonstrated based on the “search and scan” process.
The possibility of combining the proposed indoor optical wireless communication system with wavelength-division-multiplexing (WDM) technology to realize an ultra-broadband system in personal areas is investigated in this thesis. Up to 4 × 12.5 Gbps error-free (BER < 10-9) data transmission is achieved. Furthermore, the impact of optical crosstalk is analyzed both theoretically and experimentally. In addition, since most of the already installed in-building fiber distribution networks employ multi-mode fiber (MMF), the feasibility of incorporating the proposed system with MMF is experimentally verified.
It is found that background light is one of the major limiting factors in the proposed system and a novel single channel imaging receiver (SCIR) is proposed in the thesis. Experimental results show better performance can be achieved with SCIR and the improvement in terms of error-free (BER < 10-9) beam footprint is > 20%. Furthermore, better indoor localization accuracy can be realized with single channel imaging receiver.
In addition, the data centers and high performance computing are now encountering the “interconnect bottleneck” using the…
Subjects/Keywords: optical wireless technology; indoor communications; optical interconnects
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
WANG, K. (2013). Optical wireless technologies for high-speed indoor communications and interconnects. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/38706
Chicago Manual of Style (16th Edition):
WANG, KE. “Optical wireless technologies for high-speed indoor communications and interconnects.” 2013. Doctoral Dissertation, University of Melbourne. Accessed January 16, 2021.
http://hdl.handle.net/11343/38706.
MLA Handbook (7th Edition):
WANG, KE. “Optical wireless technologies for high-speed indoor communications and interconnects.” 2013. Web. 16 Jan 2021.
Vancouver:
WANG K. Optical wireless technologies for high-speed indoor communications and interconnects. [Internet] [Doctoral dissertation]. University of Melbourne; 2013. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11343/38706.
Council of Science Editors:
WANG K. Optical wireless technologies for high-speed indoor communications and interconnects. [Doctoral Dissertation]. University of Melbourne; 2013. Available from: http://hdl.handle.net/11343/38706
University of Arizona
15.
Gao, Wenbo.
Application of Spatial Modes in Advanced Optical Communications and Networking
.
Degree: 2018, University of Arizona
URL: http://hdl.handle.net/10150/628425
► To satisfy the ever-increasing demands for high speed networks, the spatial dimension is exploited to increase the capacity of the communication systems. Optical waves with…
(more)
▼ To satisfy the ever-increasing demands for high speed networks, the spatial dimension is exploited to increase the capacity of the communication systems.
Optical waves with spatial orthogonality can serve as independent transmission channels after they are multiplexed together, and this technique is called as spatial division multiplexing (SDM). SDM can be realized in both fiber and free space
optical channels. Spatial modes can consist of: multiple parallel beams in a multicore fiber, different orders of the fiber’s eigenmodes in a multimode fiber, and orthogonal modes, such as Laguerre Gaussian modes. Although SDM is a very promising option to achieve a large capacity network, however there are still many problems to be solved before it can be implemented in real applications. In this dissertation, SDM is investigated from the transmission level to the network level perspective.
In the first part of this dissertation, we have verified a strong correlation between the crosstalk intensity and the statistical characterization of the signal in
optical fibers and developed a novel method for monitoring in-service channel crosstalk. Also, as for the application in the free space
optical channels (FSO), by adopting the Kolmogorov model of turbulence we established and experimentally verified a relationship between the wavefront error variance and the phase structure function that can be directly applied to estimate the atmospheric coherence diameter and the refraction-index structure constant.
The second part of the dissertation focuses on SDM employment in two relevant topologies of
optical networks (i.e. metro/core segment and a comprehensive architecture that consists of core/metro and access network segments). We investigated and proposed an optimized design and assignment strategy for the resource allocation in multidimensional networking structure with plurality of spectral and spatial components that also includes a dynamic interaction between spectral and spatial modes.
Advisors/Committee Members: Cvijetic, Milorad (advisor), Takashima, Yuzuru (committeemember), Kieu, Khanh (committeemember).
Subjects/Keywords: optical communications;
optical network;
spatial division multiplexing
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gao, W. (2018). Application of Spatial Modes in Advanced Optical Communications and Networking
. (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/628425
Chicago Manual of Style (16th Edition):
Gao, Wenbo. “Application of Spatial Modes in Advanced Optical Communications and Networking
.” 2018. Doctoral Dissertation, University of Arizona. Accessed January 16, 2021.
http://hdl.handle.net/10150/628425.
MLA Handbook (7th Edition):
Gao, Wenbo. “Application of Spatial Modes in Advanced Optical Communications and Networking
.” 2018. Web. 16 Jan 2021.
Vancouver:
Gao W. Application of Spatial Modes in Advanced Optical Communications and Networking
. [Internet] [Doctoral dissertation]. University of Arizona; 2018. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10150/628425.
Council of Science Editors:
Gao W. Application of Spatial Modes in Advanced Optical Communications and Networking
. [Doctoral Dissertation]. University of Arizona; 2018. Available from: http://hdl.handle.net/10150/628425
Nelson Mandela Metropolitan University
16.
Boiyo, Duncan Kiboi.
Optimization of flexible spectrum in optical transport networks.
Degree: Faculty of Science, 2017, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/14609
► The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from…
(more)
▼ The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from fibre-linked terminals. The eventual outcome of the high demand for broadband is strained optical and electronic devices. The backbone optical fibre transport systems and techniques such as dense wavelength division multiplexing (DWDM), higher modulation formats, coherent detection and signal amplification have increased both fibre capacity and spectrum efficiency. A major challenge to fibre capacity and spectrum efficiency is fibre-faults and optical impairments, network management, routing and wavelength assignment (RWA). In this study, DWDM and flexible spectrum techniques such as wavelength assignment and adjustment, wavelength conversion and switching, optical add and drop multiplexing (OADM) and bitrate variable transmission have been experimentally optimized in a laboratory testbed for short- and long-haul optical fibre networks. This work starts by experimentally optimising different transmitters, fibre-types and receivers suitable for implementing cost effective and energy efficient flexible spectrum networks. Vertical cavity surface-emitting lasers (VCSELs) and distributed feedback (DFB) lasers have been studied to provide up to 10 Gb/s per channel in 1310 nm and 1550 nm transmission windows. VCSELs provide wavelength assignment and adjustment. This work utilises the non-return-to-zero (NRZ) on-off keying (OOK) modulation technique and direct detection due to their cost and simplicity. By using positive intrinsic negative (PIN) photo-receivers with error-free BER sensitivity of -18±1 dBm at the acceptable 10-9-bit error rate (BER) threshold level, unamplified transmission distances between 6 km and 76 km have been demonstrated using G.652 and G.655 single mode fibres (SMFs). For the first time, an all optical VCSEL to VCSEL wavelength conversion, switching, transmission at the 1550 nm window and BER evaluation of a NRZ data signal is experimentally demonstrated. With VCSEL wavelength conversion and switching, wavelength adjustments to a spectrum width of 4.8 nm (600 GHz) can be achieved to provide alternative routes to signals when fibre-cuts and wavelength collision occurs therefore enhancing signal continuity. This work also demonstrates a technique of removing and adding a wavelength in a bundle of DWDM and flexible channels using an OADM. This has been implemented using a VCSEL and a fibre Bragg grating (FBG) providing a wavelength isolation ratio of 31.4 dB and ~0.3 𝑑𝐵 add/drop penalty of 8.5 Gb/s signal. As a result, an OADM improves spectrum efficiency by offering wavelength re-use. Optical impairments such as crosstalk, chromatic dispersion (CD) and effects of polarization mode dispersion (PMD) have been experimentally investigated and mitigated. This work showed that crosstalk penalty increased with fibre-length, bitrate, interfering signal power and reduced channel spacing and as a result, a crosstalk-penalty trade-off is…
Subjects/Keywords: Digital communications; Optical fiber communication; Optical communications; Fiber optics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Boiyo, D. K. (2017). Optimization of flexible spectrum in optical transport networks. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/14609
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Boiyo, Duncan Kiboi. “Optimization of flexible spectrum in optical transport networks.” 2017. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/14609.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Boiyo, Duncan Kiboi. “Optimization of flexible spectrum in optical transport networks.” 2017. Web. 16 Jan 2021.
Vancouver:
Boiyo DK. Optimization of flexible spectrum in optical transport networks. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2017. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/14609.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Boiyo DK. Optimization of flexible spectrum in optical transport networks. [Thesis]. Nelson Mandela Metropolitan University; 2017. Available from: http://hdl.handle.net/10948/14609
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Hong Kong University of Science and Technology
17.
Duong, Huu Kinh Luan.
Crosstalk noise analysis in ring-based optical networks-on-chip.
Degree: 2014, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-87376
;
https://doi.org/10.14711/thesis-b1333703
;
http://repository.ust.hk/ir/bitstream/1783.1-87376/1/th_redirect.html
► Optical networks-on-chip, ONoCs, has been proposed for ultra-high bandwidth and low latency. Different ONoCs are constructed by the microresonators. One of the drawbacks of these…
(more)
▼ Optical networks-on-chip, ONoCs, has been proposed for ultra-high bandwidth and low latency. Different ONoCs are constructed by the microresonators. One of the drawbacks of these microresonators is that they suffer from intrinsic crosstalk noise and power loss, resulting in the reduction of Signal-to-Noise Ratio (SNR) which causes system performance degradation at the network level. Among the different topologies of ONoCs, ring-based networks-on-chip has been introduced because it utilizes on-chip crossbars providing the on-chip bandwidth. These on-chip crossbars can improve the network latency when the electrical-optical/optical-electrical converters are placed only at the end of the ring. With this characteristic, the on-chip crossbars may suffer from a large amount of crosstalk noise accumulated from the first to the last cluster. Hence, in this thesis, we systematically study the worst-case crosstalk noise and SNR in ring-based ONoCs. For the first time, we formally propose the analytical models at the device level for a DWDM ONoC and utilize a bottom-up approach to analyze the crosstalk noise as well as the SNR of a ring-based ONoC at the network level. Finally, we apply these analyses to simulate the quantitative results of the worst-case power loss, crosstalk noise, and SNR in two different ring-based ONoCs, which are Corona and SUOR the Sectioned Undirectional Optical Ring. The thesis focuses more on the results of Corona ONoC. We also provide comparison of the worst-case SNR and signal power loss among Corona, mesh-based and folded-torus-based ONoCs, all of which consist of the same number of cores. The quantitative results demonstrate the damaging impact of crosstalk noise and power loss in Corona: the worst-case SNR is 14.0 dB in the network, while the worst-case power loss is substantially high, -69.3 dB, in the data channel. Regarding the control arbitration, the worstcase SNR in Corona is noticeably high at -139.26dB. Meanwhile, the worst-case results of SUOR shows that this network provides a competitive signal power loss, at -15.5dB, while keeping the worst-case SNR high, at 11.8dB, compared to Corona and other ONoCs.
Subjects/Keywords: Networks on a chip
; Optical properties
; Digital communications
; Noise
; Optical communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Duong, H. K. L. (2014). Crosstalk noise analysis in ring-based optical networks-on-chip. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-87376 ; https://doi.org/10.14711/thesis-b1333703 ; http://repository.ust.hk/ir/bitstream/1783.1-87376/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Duong, Huu Kinh Luan. “Crosstalk noise analysis in ring-based optical networks-on-chip.” 2014. Thesis, Hong Kong University of Science and Technology. Accessed January 16, 2021.
http://repository.ust.hk/ir/Record/1783.1-87376 ; https://doi.org/10.14711/thesis-b1333703 ; http://repository.ust.hk/ir/bitstream/1783.1-87376/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Duong, Huu Kinh Luan. “Crosstalk noise analysis in ring-based optical networks-on-chip.” 2014. Web. 16 Jan 2021.
Vancouver:
Duong HKL. Crosstalk noise analysis in ring-based optical networks-on-chip. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2014. [cited 2021 Jan 16].
Available from: http://repository.ust.hk/ir/Record/1783.1-87376 ; https://doi.org/10.14711/thesis-b1333703 ; http://repository.ust.hk/ir/bitstream/1783.1-87376/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Duong HKL. Crosstalk noise analysis in ring-based optical networks-on-chip. [Thesis]. Hong Kong University of Science and Technology; 2014. Available from: http://repository.ust.hk/ir/Record/1783.1-87376 ; https://doi.org/10.14711/thesis-b1333703 ; http://repository.ust.hk/ir/bitstream/1783.1-87376/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
McMaster University
18.
Ahmed, Khaled.
Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks.
Degree: PhD, 2019, McMaster University
URL: http://hdl.handle.net/11375/24831
► The increasing demand on user rates in the fifth generation (5G) requires network architectures that can support high data rates with acceptable reliability. In order…
(more)
▼ The increasing demand on user rates in the fifth generation (5G) requires network architectures
that can support high data rates with acceptable reliability. In order to increase
the data rates in the presence of the current spectrum crisis, shrinking cells and reusing the
spectrum is a proposed solution. Conventional implementation of dense cells requires a
large number of expensive BSs to locally process and decode users’ signals. Another limiting
factor that degrades the performance in a dense network is the inter-cell interference.
A cloud radio access network (CRAN) is a promising solution to those cost, complexity,
and interference challenges. A typical CRAN architecture consists of simplified low-cost
base stations (BSs), termed radio units (RUs), that collect the radio frequency (RF) user
equipments’ (UEs) signals and forward them over the fronthaul links to the central office
(CO) where signal processing is done over shared resources. Besides the reduced cost and
complexity of a CRAN, the joint processing at the CO enables joint interference mitigation
techniques. However, the performance of CRANs depends critically on the availability of
reliable fronthaul links with large bandwidth that may be expensive. Analog
optical fronthaul
links provide high data rates at lower cost and complexity since UEs’ signals are
optically analog-modulated without digitalization, however, they suffer from other channel
impairments and nonlinearities.
In this thesis, analog
optical fronthaul topologies are considered in which radio signals are forwarded over free-space
optical (FSO) links, termed radio-over-free-space
optical
(RoFSO) links, and
optical fiber (OF) links, termed radio-over-fiber (RoF) links.
Firstly, a CRAN with mixed RF/RoFSO fronthaul is considered to investigate the performance
improvement when RF fronthaul links are replaced one-by-one by RoFSO links.
A novel joint optimization problem is introduced for the given architecture in which the
weighted sum of UEs’ rates is maximized by jointly designing RF and RoFSO links. The
optimization problem is solved over different numbers of RF and RoFSO links and under
various weather conditions. Under favorable weather conditions, the replacement of 1 RF
link by a RoFSO link is shown to increase the 50th percentile of UEs’ rates by 7 times.
Secondly, the reliability of a CRAN with two-hop RoFSO/RoF fronthaul links is derived
along with other performance metrics such as the average bit-error rate and the cumulative
distribution function of UEs’ rates. For the given architecture, the Gaussian noise
model of fiber nonlinearity is applied and an optimal OF average
optical power is derived
to minimize the outage probability. Using the optimal power, and under favorable weather
conditions, the 50th percentile of user rate exceeds 1:5 Gbps.
Finally, a CRAN with passive all-
optical two-hop fronthaul links is considered where
optical signals from the first RoFSO fronthaul hop are passively coupled into the RoF fronthaul
link. The fronthaul outage…
Advisors/Committee Members: Hranilovic, Steve, Electrical and Computer Engineering.
Subjects/Keywords: Free-space optical communications; Cloud radio access network; optical communications; optical fiber
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ahmed, K. (2019). Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/24831
Chicago Manual of Style (16th Edition):
Ahmed, Khaled. “Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks.” 2019. Doctoral Dissertation, McMaster University. Accessed January 16, 2021.
http://hdl.handle.net/11375/24831.
MLA Handbook (7th Edition):
Ahmed, Khaled. “Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks.” 2019. Web. 16 Jan 2021.
Vancouver:
Ahmed K. Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks. [Internet] [Doctoral dissertation]. McMaster University; 2019. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11375/24831.
Council of Science Editors:
Ahmed K. Radio-over-Free-Space Optical Fronthauling for Cloud Radio Access Networks. [Doctoral Dissertation]. McMaster University; 2019. Available from: http://hdl.handle.net/11375/24831
Hong Kong University of Science and Technology
19.
Duong, Huu Kinh Luan ECE.
Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks.
Degree: 2018, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-102348
;
https://doi.org/10.14711/thesis-991012588464903412
;
http://repository.ust.hk/ir/bitstream/1783.1-102348/1/th_redirect.html
► With the increasing number of processing cores on a single die, the traditional Networks-on-Chip (NoCs) interconnects hardly keep up with the demands of high-bandwidth and…
(more)
▼ With the increasing number of processing cores on a single die, the traditional Networks-on-Chip (NoCs) interconnects hardly keep up with the demands of high-bandwidth and low-latency communication. Various optical interconnection networks [1–3] with the optical on-chip optical crossbars have been proposed to meet the ultra-high on-chip bandwidth requirements. More recently, optical interconnection networks have been further developed, where they have not only covered the intra-chip but also inter-chip communication. These networks consist of two different interconnection parts: the optical intra-chip and inter-chip for on-chip and among-the-chips communication, respectively. An inter/intra-chip optical interconnection network, I2CON, was proposed in [4]. It consisted of two different interconnection parts: the optical inter-chip network and the optical intra-chip network. One key issue for these WDM inter/intra-chip optical interconnection network is the crosstalk noise. Crosstalk noise is an intrinsic characteristic of the optical components. Depending on the architecture of the network, the crosstalk noise can be intensified among numerous optical components in various combinations. Moreover, with the presence of a large number of wavelengths in one single waveguide (i.e. WDM-based), crosstalk noise from different wavelengths may affect the detected signal on a wavelength. Hence, in this thesis, we analyze the crosstalk noise and its impact on the SNR of the inter/intra-chip optical interconnection network. We also investigate a method, called Adaptive Power Control (APC) in order to reduce the crosstalk noise. We demonstrate the effect of this method in a candidate of the inter/intra-chip optical interconnection network, called I2CON.
Subjects/Keywords: Optical interconnects
; Noise
; Networks on a chip
; Optical properties
; Optical communications
; Digital communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Duong, H. K. L. E. (2018). Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-102348 ; https://doi.org/10.14711/thesis-991012588464903412 ; http://repository.ust.hk/ir/bitstream/1783.1-102348/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Duong, Huu Kinh Luan ECE. “Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks.” 2018. Thesis, Hong Kong University of Science and Technology. Accessed January 16, 2021.
http://repository.ust.hk/ir/Record/1783.1-102348 ; https://doi.org/10.14711/thesis-991012588464903412 ; http://repository.ust.hk/ir/bitstream/1783.1-102348/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Duong, Huu Kinh Luan ECE. “Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks.” 2018. Web. 16 Jan 2021.
Vancouver:
Duong HKLE. Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2018. [cited 2021 Jan 16].
Available from: http://repository.ust.hk/ir/Record/1783.1-102348 ; https://doi.org/10.14711/thesis-991012588464903412 ; http://repository.ust.hk/ir/bitstream/1783.1-102348/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Duong HKLE. Crosstalk noise analyses and mitigation in inter/intra-chip optical interconnection networks. [Thesis]. Hong Kong University of Science and Technology; 2018. Available from: http://repository.ust.hk/ir/Record/1783.1-102348 ; https://doi.org/10.14711/thesis-991012588464903412 ; http://repository.ust.hk/ir/bitstream/1783.1-102348/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Hong Kong University of Science and Technology
20.
Sayarath, Aimé.
Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications.
Degree: 2011, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-7450
;
https://doi.org/10.14711/thesis-b1160577
;
http://repository.ust.hk/ir/bitstream/1783.1-7450/1/th_redirect.html
► In this thesis, we model and experimentally demonstrate a number of silicon microring resonator-based optical switches and optical delay lines. We propose silicon feedback-waveguide-coupled microring…
(more)
▼ In this thesis, we model and experimentally demonstrate a number of silicon microring resonator-based optical switches and optical delay lines. We propose silicon feedback-waveguide-coupled microring resonator-based devices for optical switching and hitless tuning. We also measure the optical delay in the fabricated feedback-waveguide coupled microring resonator. Finally, we demonstrate a proof-of-concept experiment of a 3×3 matrix switch used as an optical router. We propose a silicon feedback-waveguide-coupled microring for optical filtering. Our proof-of-concept experiment shows an extinction ratio modulation from 0 dB to 18 dB at a fixed wavelength with a resonance Q of 4000. We propose to further improve the device performance by using a large number of coupled microrings and implement a Vernier-effect design. We model a feedback-waveguide-based fourth-order hitless filter showing a FSR larger than 32 nm, a 43 dB channel extinction ratio, a 3 dB-bandwidth of 12 GHz and a 12 dB channel isolation, which is potentially useful for wavelength-division-multiplexing optical communications. We present time-domain measurements of 1 Gbit/s and 10 Gbit/s time delayed Non-Return-to-Zero-signals in a feedback-waveguide-coupled microring resonator device. We demonstrate a maximum of 37 ps and 28 ps time delays for 1 Gb/s and 10 Gb/s bit rates respectively, with open eye-diagrams. We also model a delayed NRZ-modulated signal based on the Fourier-transform analysis and the modeling results show consistency with the experimental results. Finally, we experimentally demonstrate an electro-optical 3×3 matrix switch using microring resonators fabricated on a silicon-on-insulator substrate. Among the array of nine microrings, the five functional microrings enable the setup of multiple routes for the input light as a proof-of-concept. The device shows sub-nanosecond switch-on and –off times for optical paths establishment.
Subjects/Keywords: Wavelength division multiplexing
; Resonators
; Optical resonance
; Optical communications
; Silicon – Optical properties
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sayarath, A. (2011). Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-7450 ; https://doi.org/10.14711/thesis-b1160577 ; http://repository.ust.hk/ir/bitstream/1783.1-7450/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sayarath, Aimé. “Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications.” 2011. Thesis, Hong Kong University of Science and Technology. Accessed January 16, 2021.
http://repository.ust.hk/ir/Record/1783.1-7450 ; https://doi.org/10.14711/thesis-b1160577 ; http://repository.ust.hk/ir/bitstream/1783.1-7450/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sayarath, Aimé. “Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications.” 2011. Web. 16 Jan 2021.
Vancouver:
Sayarath A. Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2011. [cited 2021 Jan 16].
Available from: http://repository.ust.hk/ir/Record/1783.1-7450 ; https://doi.org/10.14711/thesis-b1160577 ; http://repository.ust.hk/ir/bitstream/1783.1-7450/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sayarath A. Silicon microring resonator-based devices for wavelength-division-multiplexing optical communications. [Thesis]. Hong Kong University of Science and Technology; 2011. Available from: http://repository.ust.hk/ir/Record/1783.1-7450 ; https://doi.org/10.14711/thesis-b1160577 ; http://repository.ust.hk/ir/bitstream/1783.1-7450/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Southern California
21.
Maor, Asher.
Sweep-free Brillouin optical time-domain analyzer.
Degree: PhD, Electrical Engineering, 2015, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/530379/rec/6260
► Brillouin-based optical fiber sensing is a promising technology for the monitoring of many types of structural and environmental changes. Sensors based on this technology use…
(more)
▼ Brillouin-based
optical fiber sensing is a promising
technology for the monitoring of many types of structural and
environmental changes. Sensors based on this technology use the
Brillouin nonlinear process in which acoustic phonons in the fiber
either spontaneously scatter a forward propagating
optical wave
(called 'pump') into a backward propagating wave (called 'probe'),
or, alternatively, mediate, via a stimulated interaction, power
transfer between counter propagating waves ('pump' and 'probe'). In
either case, the returning light has a characteristic frequency
shift (from that of the pump), which varies with many types of
changes in the propagating medium, such as temperature and
mechanical stress. Therefore, this Brillouin frequency shift (BFS)
can provide information on the surrounding temperature and strain
distributions along an
optical fiber. ❧ There are several major
schemes for Brillouin-based
optical fiber sensors, including
Brillouin
optical time domain reflectometers (BOTDRs), Brillouin
optical time domain analyzers (BOTDAs), and Brillouin
optical
correlation-domain analyzers (BOCDAs). BOTDRs mostly use a
single-ended implementation, where a pump wave gives rise to a
spontaneous Brillouin back-scattered probe, whose
optical frequency
is measured via a variety of techniques. The
optical power level of
the backscattered wave is weak, requiring averaging of multiple
measurements (i.e., integrations) in order to reach a sufficiently
high signal-to-noise ratio (SNR). This may cause longer sensing
times of up to several minutes. BOTDAs sensors rely on the
stimulated Brillouin scattering (SBS) process in which two
counter-propagating pump and probe waves generate acoustic waves in
the fiber, which then transfer
optical power from the pump to the
probe if the latter frequency is downshifted from that of the pump
by the BFS. Since the emerging probe is typically stronger in
BOTDAs than in BOTDRs, shorter sensing times are achievable.
Finally, BOCDAs are SBS-based sensors in which counter-propagating
probe and pump waves produce spatially correlated interference
peaks along the fiber to dramatically improve the spatial
resolution. BOCDAs can also sense the dynamic variation of the
environmental changes up to 1 KHz, but this is typically limited to
local stimulation along fiber sections. ❧ In many Brillouin-based
sensors, e.g., BOTDAs, the evolution of temperature/strain induced
BFS is determined from consecutive recordings of the whole
Brillouin gain spectrum (BGS). This Lorentzian-shaped spectrum,
having a width of ~30MHz (FWHM) at 1550nm in a standard single mode
optical fiber (SMF), must be measured as densely as the application
requires. Typically the sensitivity of the BFS is 1MHz/⁰C and
500MHz/(1% strain). Classically, the BGS is measured by sweeping
the
optical frequency of either the pump or the probe, over the
entire BGS. Since the probe signal is quite weak, especially when
long (tens of kilometers) fibers are interrogated, averaging over
multiple measurements is required at each frequency point,…
Advisors/Committee Members: Willner, Alan E. (Committee Chair), Sawchuk, Alexander A. (Sandy) (Committee Member), Udwadia, Firdaus E. (Committee Member).
Subjects/Keywords: Brillouin scattering; FDM; optical communications; optical fibers; optical fiber sensors
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Maor, A. (2015). Sweep-free Brillouin optical time-domain analyzer. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/530379/rec/6260
Chicago Manual of Style (16th Edition):
Maor, Asher. “Sweep-free Brillouin optical time-domain analyzer.” 2015. Doctoral Dissertation, University of Southern California. Accessed January 16, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/530379/rec/6260.
MLA Handbook (7th Edition):
Maor, Asher. “Sweep-free Brillouin optical time-domain analyzer.” 2015. Web. 16 Jan 2021.
Vancouver:
Maor A. Sweep-free Brillouin optical time-domain analyzer. [Internet] [Doctoral dissertation]. University of Southern California; 2015. [cited 2021 Jan 16].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/530379/rec/6260.
Council of Science Editors:
Maor A. Sweep-free Brillouin optical time-domain analyzer. [Doctoral Dissertation]. University of Southern California; 2015. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/530379/rec/6260
University of Pretoria
22.
[No author].
An RF bandwidth switch for multimedia
transmission
.
Degree: 2006, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-12182006-153101/
Please read the abstract in the section 00front of
this document
Advisors/Committee Members: Prof J J D van Schalkwyk (advisor).Subjects/Keywords: Optical communications.;
UCTD
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2006). An RF bandwidth switch for multimedia
transmission
. (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-12182006-153101/
Chicago Manual of Style (16th Edition):
author], [No. “An RF bandwidth switch for multimedia
transmission
.” 2006. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://upetd.up.ac.za/thesis/available/etd-12182006-153101/.
MLA Handbook (7th Edition):
author], [No. “An RF bandwidth switch for multimedia
transmission
.” 2006. Web. 16 Jan 2021.
Vancouver:
author] [. An RF bandwidth switch for multimedia
transmission
. [Internet] [Masters thesis]. University of Pretoria; 2006. [cited 2021 Jan 16].
Available from: http://upetd.up.ac.za/thesis/available/etd-12182006-153101/.
Council of Science Editors:
author] [. An RF bandwidth switch for multimedia
transmission
. [Masters Thesis]. University of Pretoria; 2006. Available from: http://upetd.up.ac.za/thesis/available/etd-12182006-153101/
Nelson Mandela Metropolitan University
23.
Gamatham, Romeo Reginald Gunther.
Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks.
Degree: Faculty of Science, 2013, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/6302
► The demand for faster data transmission is ever increasing. Wavelength division multiplexing (WDM) presents as a viable solution to increase the data transmission rate significantly.…
(more)
▼ The demand for faster data transmission is ever increasing. Wavelength division multiplexing (WDM) presents as a viable solution to increase the data transmission rate significantly. WDM systems are based on the ability to transmit multiple wavelengths simultaneously down the fibre. Unlike time division multiplexing (TDM) systems, WDM systems do not increase the data transfer by increasing the transmission rate of a single channel. In WDM systems the data rate per channel remains the same, only multiple channels carry data across the link. Dense wavelength division multiplexing (DWDM) promises even more wavelengths packed together in the same fibre. This multiplication of channels increases the bandwidth capacity rapidly. Networks are looking into making use of technology that will ensure no electronic signal regeneration at any point within the DWDM network. Examples are; reconfigurable optical add/drop multiplexers (ROADM) and optical cross connect (OXC) units. These components essentially enable network operators to split, combine and multiplex optical signals carried by optical fibre. WDM allows network operators to increase the capacity of existing networks without expensive re-cabling. This provides networks with the flexibility to be upgraded to larger bandwidths and for reconfiguration of network services. Further, WDM technology opens up an opportunity of marketing flexibility to network operators, where operators not only have the option to rent out cables and fibres but wavelengths as well. Cross phase modulation (XPM) poses a problem to WDM networks. The refractive index experienced by a neighbouring optical signal, not only depends on the signal’s intensity but on the intensity of the co-propagating signal as well. This effect leads to a phase change and is known as XPM. This work investigates the characteristics of XPM. It is shown that, in a two channel WDM network, a probe signal’s SOP can be steered by controlling a high intensity pump signal’s SOP. This effect could be applied to make a wavelength converter. Experimental results show that the degree of polarization (DOP) of a probe signal degrades according to a mathematical model found in literature. The pump and probe signals are shown to experience maximum interaction, for orthogonal probe-pump SOP vector orientations. This may be problematic to polarization mode dispersion compensators. Additionally, experimental results point out that the SOP of a probe signal is much more active in the presence of a high intensity pump, as compared to the single signal transmission scenario.
Subjects/Keywords: Wavelength division multiplexing; Optical communications; Fiber optics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gamatham, R. R. G. (2013). Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/6302
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gamatham, Romeo Reginald Gunther. “Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks.” 2013. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/6302.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gamatham, Romeo Reginald Gunther. “Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks.” 2013. Web. 16 Jan 2021.
Vancouver:
Gamatham RRG. Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2013. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/6302.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gamatham RRG. Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks. [Thesis]. Nelson Mandela Metropolitan University; 2013. Available from: http://hdl.handle.net/10948/6302
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Nelson Mandela Metropolitan University
24.
Chabata, Tichakunda Valentine.
Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver.
Degree: Faculty of Science, 2016, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/4775
► The drastic increase in the number of internet users and the general convergence of all other communication systems into an optical system have brought a…
(more)
▼ The drastic increase in the number of internet users and the general convergence of all other communication systems into an optical system have brought a sharp rise in demand for bandwidth and calls for high capacity transmission networks. Large unamplified transmission reach is another contributor in reducing deployment costs of an optical communication system. Spectrally efficient modulation formats are suggested as a solution to overcome the problems associated with limited channels and bandwidth of dense wavelength division multiplexing (DWDM) optical communication systems. Higher order modulation formats which are considered to be spectrally efficient and can increase the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all was studied. Different detection technologies are to be implemented to suit a particular higher order modulation format. In this research multilevel modulation formats, different detection technologies and a digital signal processing aided receiver were studied in a practical optical transmission system. The work in this thesis started with the implementation of the traditional amplitude shift keying (ASK) modulation and a differential phase shift keying (DPSK) modulation systems as they form the basic building block in the design of higher order modulation formats. Results obtained from using virtual photonics instruments (VPI)simulation software, receiver sensitivity for 10Gbpsnon-return-to-zero (NRZ), amplitude phase shift keying (ASK) and DPSK signals were measured to be -22.7 dBm and -22.0 dBm respectively. Performance comparison for the two modulation formats were done over different transmission distances. ASK also known as On-Off keying (OOK) performed better for shorter lengths whereas DPSK performed better for longer lengths of up to90km.Experimental results on a 10 Gbps NRZ- ASK signal gave a receiver sensitivity of -21.1 dBm from digital signal processing (DSP) aided receiver against -19.8 dBm from the commercial bit error ratio tester (BERT) yielding a small difference of 1.3 dB hence validating the reliability and accuracy of the digital signal processing (DSP) assisted receiver. Traditional direct detection scheme and coherent detection scheme performances were evaluated again on a 10 Gbps NRZ ASK signal. Coherent detection that can achieve a large unamplified transmission reach and has a higher passive optical splitting ratio was first evaluated using the VPI simulation software. Simulation results gave a receiver sensitivity of -30.4 dBm forcoherent detection and -18.3 dBm for direct detection, yielding a gain in receiver sensitivity of 12.1 dB. The complex coherently detected signal, from the experimental setup gave a receiver sensitivity of -20.6 dBm with a gain in receiver sensitivity of 3.5 dBm with respect to direct detection. A multilevel pulse amplitude modulation (4-PAM) that doubles the data rate per channel from10 Gbps to 20 Gbps by transmitting more information in the amplitude of the carrier signal…
Subjects/Keywords: Optical communications; Modulation (Electronics); Signal processing
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chabata, T. V. (2016). Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/4775
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chabata, Tichakunda Valentine. “Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver.” 2016. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/4775.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chabata, Tichakunda Valentine. “Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver.” 2016. Web. 16 Jan 2021.
Vancouver:
Chabata TV. Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2016. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/4775.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chabata TV. Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver. [Thesis]. Nelson Mandela Metropolitan University; 2016. Available from: http://hdl.handle.net/10948/4775
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Alberta
25.
Vethanayagam, Niranjan.
Demonstration of a novel code division multiple access
system at 800 MChips/s.
Degree: MS, Department of Electrical Engineering, 1991, University of Alberta
URL: https://era.library.ualberta.ca/files/5d86p216d
Subjects/Keywords: Optical communications.; Optoelectronics.
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Vethanayagam, N. (1991). Demonstration of a novel code division multiple access
system at 800 MChips/s. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/5d86p216d
Chicago Manual of Style (16th Edition):
Vethanayagam, Niranjan. “Demonstration of a novel code division multiple access
system at 800 MChips/s.” 1991. Masters Thesis, University of Alberta. Accessed January 16, 2021.
https://era.library.ualberta.ca/files/5d86p216d.
MLA Handbook (7th Edition):
Vethanayagam, Niranjan. “Demonstration of a novel code division multiple access
system at 800 MChips/s.” 1991. Web. 16 Jan 2021.
Vancouver:
Vethanayagam N. Demonstration of a novel code division multiple access
system at 800 MChips/s. [Internet] [Masters thesis]. University of Alberta; 1991. [cited 2021 Jan 16].
Available from: https://era.library.ualberta.ca/files/5d86p216d.
Council of Science Editors:
Vethanayagam N. Demonstration of a novel code division multiple access
system at 800 MChips/s. [Masters Thesis]. University of Alberta; 1991. Available from: https://era.library.ualberta.ca/files/5d86p216d
Nelson Mandela Metropolitan University
26.
Musara, Vitalis.
Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems.
Degree: Faculty of Science, 2009, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/1138
► In this study, focus is centred on the measurement and emulation of first-order (FO-) and second-order (SO-) polarization mode dispersion (PMD). PMD has deleterious effects…
(more)
▼ In this study, focus is centred on the measurement and emulation of first-order (FO-) and second-order (SO-) polarization mode dispersion (PMD). PMD has deleterious effects on the performance of high speed optical transmission network systems from 10 Gb/s and above. The first step was characterising deployed fibres for PMD and monitoring the state of polarization (SOP) light experiences as it propagates through the fibre. The PMD and SOP changes in deployed fibres were stochastic due to varying intrinsic and extrinsic perturbation changes. To fully understand the PMD phenomenon in terms of measurement accuracy, its complex behaviour, its implications, mitigation and compensation, PMD emulation is crucial. This thesis presents emulator designs which fall into different emulator categories. The key to these designs were the PMD equations and background on the PMD phenomenon. The cross product from the concatenation equation was applied in order to determine the coupling angle β (between 0o and 180o) that results in the SO-PMD of the emulator designs to be either adjustable or fixed. The digital delay line (DDL) or single polarization maintaining fibre (PMF) section was used to give a certain amount of FO-PMD but negligible SO-PMD. PMF sections (birefringent sections) were concatenated together to ensure FO- and SO-PMD coexist, emulating deployed fibres. FO- and SO-PMD can be controlled by altering mode coupling (coupling angles) and birefringence distribution. Emulators with PMD statistics approaching the theoretical distributions had high random coupling and several numbers of randomly distributed PMF sections. In addition, the lengths of their PMF sections lie within 20% standard deviation of the mean emulator length. Those emulators with PMD statistics that did not approach the theoretical distributions had limited numbers of randomly distributed PMF sections and mode coupling. Results also show that even when an emulator has high random mode coupling and several numbers of randomly distributed PMFs, its PMD statistics deviates away from expected theoretical distributions in the presence of polarization dependent loss (PDL). The emulators showed that the background autocorrelation function (BACF) approaches zero with increasing number of randomly mode coupled fibre sections. A zero BACF signifies that an emulator has large numbers of randomly distributed PMF sections and its presence means the opposite. The availability of SO-PMD in the emulators made the autocorrelation function (ACF) x asymmetric. In the absence of SO-PMD the ACF for a PMD emulator is symmetric. SO-PMD has no effect on the BACF. Polarization-optical time domain reflectometry (P-OTDR) measurements have shown that certain fibre sections along fibre link lengths have higher FO-PMD (HiFO-PMD) than other sections. This study investigates the impact of a HiFO-PMD section on the overall FO- and SO-PMD, the output state of polarization (SOP) and system performance on deployed fibres (through emulation). Results show that when the wavelength-independent…
Subjects/Keywords: Optical communications; Fiber optics; Polarization (Light)
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Musara, V. (2009). Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/1138
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Musara, Vitalis. “Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems.” 2009. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/1138.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Musara, Vitalis. “Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems.” 2009. Web. 16 Jan 2021.
Vancouver:
Musara V. Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/1138.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Musara V. Polarization mode dispersion emulation and the impact of high first-order PMD segments in optical telecommunication systems. [Thesis]. Nelson Mandela Metropolitan University; 2009. Available from: http://hdl.handle.net/10948/1138
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Penn State University
27.
Alqudah, Yazan A.
Space Diversity in Indoor Broadband Optical Wireless Communications.
Degree: 2008, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/6086
► Wireless optical (infrared) link provides a secure and a promising alternative to radio for wireless indoor connectivity, be it for terminals or sensors. The large…
(more)
▼ Wireless
optical (infrared) link provides a secure and a promising alternative to radio for wireless indoor connectivity, be it for terminals or sensors. The large spectrum of unregulated band enables a link to provide broadband access needed for multimedia and other bandwidth demanding applications. The spatial confinement of infrared light provides interference-free bandwidth-reuse in adjacent rooms. The ability to create spatially independent channels in a small physical space holds the promise of large link capacity.
The main challenges in the design of an infrared link include: susceptibility to shadowing, multipath dispersion, and limited range resulting from noise generated by ambient light. Shadowing caused by benign objects blocking signal path results in service degradation, if not complete interruption. Configurations employing wide beam transmitter to service many receiver locations suffer multipath. Noise at receiver is generated by ambient light. Even in a uniformly lit environment, noise generated by natural and artificial light varies depending on receiver location and orientation.
To combat the adverse effects of temporal dispersion in high-speed applications, an accurate channel impulse response is needed. The impulse response is used to analyze and to compensate for the effects of multipath dispersion. In this work, a new approach for obtaining the channel impulse response is presented resulting in tremendous savings in calculation time and bringing insight into the channel behavior.
The ability to create spatially independent channels has motivated a new configuration called Multi-Spot Diffusing (MSD) configuration. In which, a transmitter acts as an array antenna, with each element transmitting data over an independent channel. A multibranch receiver is employed to receive independent copies of transmitted data through each of its branches. In our research, we analyze MSD link with the objective of determining the optimal number of branches that results in maximum signal-to-noise ratio, minimum probability of error and minimum outage probability.
The MSD configuration increases link capacity and reliability by providing a multi-input multi-output channel between transceivers. The availability of N spatial channels implies the possibility of increasing data rate by N folds compared to a single channel. In order to improve link reliability, our research considers novel spatial diversity coding techniques. In orthogonal spatial coding, each channel is responsible for carrying one of N symbols. The receiver decides on a transmitted symbol by comparing received signals on its branches and selects the branch corresponding to maximum signal. In another proposed scheme, a symbol is represented by N bit code word. Each bit is transmitted through a separate channel. The diversity receiver decides on a symbol that corresponds to the highest correlation with a received code word. Thus, information is transmitted not only through signal shapes, but also through branches that receive them.
Traditionally, a…
Advisors/Committee Members: Mohsen Kavehrad, Committee Chair/Co-Chair, John Metzner, Committee Member, Shizhuo Yin, Committee Member, Natarajan Gautam, Committee Member.
Subjects/Keywords: Optical Wireless Communications
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Alqudah, Y. A. (2008). Space Diversity in Indoor Broadband Optical Wireless Communications. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/6086
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Alqudah, Yazan A. “Space Diversity in Indoor Broadband Optical Wireless Communications.” 2008. Thesis, Penn State University. Accessed January 16, 2021.
https://submit-etda.libraries.psu.edu/catalog/6086.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Alqudah, Yazan A. “Space Diversity in Indoor Broadband Optical Wireless Communications.” 2008. Web. 16 Jan 2021.
Vancouver:
Alqudah YA. Space Diversity in Indoor Broadband Optical Wireless Communications. [Internet] [Thesis]. Penn State University; 2008. [cited 2021 Jan 16].
Available from: https://submit-etda.libraries.psu.edu/catalog/6086.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Alqudah YA. Space Diversity in Indoor Broadband Optical Wireless Communications. [Thesis]. Penn State University; 2008. Available from: https://submit-etda.libraries.psu.edu/catalog/6086
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Queens University
28.
Doggart, Clayton.
Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
.
Degree: Electrical and Computer Engineering, Queens University
URL: http://hdl.handle.net/1974/15912
► This thesis focuses on two distinct investigations: filter replications and the testing of a real-time system. The filter replication section used a Finisar WaveShaper programmable…
(more)
▼ This thesis focuses on two distinct investigations: filter replications and the testing of a real-time system.
The filter replication section used a Finisar WaveShaper programmable filter, a Yenista adjustable bandpass filter and a Luna Optical Vector Analyzer to adjust the input to the WaveShaper in a feedback method. There were two different scenarios for the filter replication: bandwidth narrowing/ center frequency shift and passband impairments. Both were meant to model the effect of concatenating filters from a signal being transmitted through cascaded ROADMs.
The real-time testing section was based around using a WaveLogic 3 real-time transceiver in QPSK mode. In this setting, the transceiver sends and receives a QPSK signal, performing all of its digital signal processing in real-time. Similar to the filter replication section, the real-time performance of the WL3 transceiver was tested with bandwidth narrowing/center frequency shift as well as passband impairments. For the bandwidth narrowing, only the Yenista bandpass filter was used between the transmitter and receiver to provide the effect of bandwidth narrowing/center frequency shift. For the passband impairments, the WaveShaper and Yenista filter were used together to provide passband impairments with an adjustable bandwidth setting. Unlike the filter replication case, the WaveShaper was used in a feed-forward capacity.
For the filter replication, the metric for measuring success was the reduction of the mean squared error compared to the feedforward case. The bandwidth narrowing/center frequency shift case had limited success, with a mean MSE reduction of 16.08% and one scenario of 10 resulting in an increase in the MSE. The passband impairment filter replication was much more effective, resulting in a mean reduction in MSE of 73.53% and an improvement in all 10 scenarios.
With real-time testing, the penalty associated with narrow bandwidth filtering / center frequency shift was explored by determining the required OSNR for a BER of 1x10-3 at different bandwidths and amounts of center frequency shift. The overall range of ROSNR was 2.2 dB, after which there was breakdown in the Forward Error Correction coding.
It was found that for the passband impairments, passband ripple had a much larger effect on the performance of the system than passband slope, due to the interaction with the Erbium-Doped Fiber Amplifier. In the ranges tested, the slope was not correlated with the mean SNR, whereas the ripple amplitude was negatively correlated with the mean SNR. The ripple period was also found to influence the performance penalty.
Subjects/Keywords: Optical Communications
;
ROADM
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Doggart, C. (n.d.). Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
. (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/15912
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Doggart, Clayton. “Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
.” Thesis, Queens University. Accessed January 16, 2021.
http://hdl.handle.net/1974/15912.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Doggart, Clayton. “Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
.” Web. 16 Jan 2021.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Vancouver:
Doggart C. Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
. [Internet] [Thesis]. Queens University; [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1974/15912.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
Council of Science Editors:
Doggart C. Cascaded ROADM Filter Replication and the Effects of Statistical Variations in the Response of Cascaded ROADMs on 100 Gb/s DP-QPSK System Performance
. [Thesis]. Queens University; Available from: http://hdl.handle.net/1974/15912
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
University of Pretoria
29.
Van Rhyn, Pierre.
An RF bandwidth
switch for multimedia transmission.
Degree: Electrical, Electronic and
Computer Engineering, 2006, University of Pretoria
URL: http://hdl.handle.net/2263/30404
Please read the abstract in the section 00front of this
document
Advisors/Committee Members: Prof J J D van Schalkwyk (advisor).Subjects/Keywords: Optical
communications.;
UCTD
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Van Rhyn, P. (2006). An RF bandwidth
switch for multimedia transmission. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/30404
Chicago Manual of Style (16th Edition):
Van Rhyn, Pierre. “An RF bandwidth
switch for multimedia transmission.” 2006. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://hdl.handle.net/2263/30404.
MLA Handbook (7th Edition):
Van Rhyn, Pierre. “An RF bandwidth
switch for multimedia transmission.” 2006. Web. 16 Jan 2021.
Vancouver:
Van Rhyn P. An RF bandwidth
switch for multimedia transmission. [Internet] [Masters thesis]. University of Pretoria; 2006. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/2263/30404.
Council of Science Editors:
Van Rhyn P. An RF bandwidth
switch for multimedia transmission. [Masters Thesis]. University of Pretoria; 2006. Available from: http://hdl.handle.net/2263/30404
Nelson Mandela Metropolitan University
30.
[No author].
Fibre optic network supporting high speed transmission in the square kilometre array, South Africa.
Degree: Faculty of Science, 2015, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/6552
► This thesis provides in-depth information on the high speed optical transport requirements for the Square Kilometre Array. The stringent data rates as well as timing…
(more)
▼ This thesis provides in-depth information on the high speed optical transport requirements for the Square Kilometre Array. The stringent data rates as well as timing and synchronization requirements are dealt with respect to the optical fibre technology. Regarding the data transport, we draw a clear comparison between a typical telecommunication access network and a telescope network. Invoking simulations and experiments on the field and laboratory test bed, we successfully implement a suitable telescope network using vertical cavity surface emitting laser (VCSEL) technology. Polarization effects on the KAT-7 telescope network, an operational prototype for the SKA is studied so as to estimate the expected effect in the MeerKAT telescope with transmission distances _ 12 km. The study further relates the obtained values to the expected impact on the distribution of the time and frequency reference in the MeerKAT array. Clock stability depends on the differential group delay (DGD) and polarization stability. On a 10:25 km link that includes the riser cable a DGD of 62:1 fs was attained. This corresponds to a polarization mode dispersion (PMD) coefficient of 19:4 fs=km1=2. This is a low PMD value considering telecommunication network. The PMD value is within the allowed budget in the telescope network. However, this may not be the case at longer baselines extending to over 1000 km as expected in SKA 2. The fibre's deployment contribution to the DGD is measured by comparing the deployed fibre to the undeployed of equal lengths. On the 10:25 km deployed single mode fibre, the maximum and mean DGDs measured were 217:7 fs and 84:8 fs respectively. The undeployed fibre of similar type and equal length, gave a maximum and minimum DGDs of 58:6 fs and 36:3 fs respectively. The deployment is seen to increase the maximum and minimum DGDs by factors of 3.7 and 2.3 respectively. This implies that fibre deployment is very critical in ensuring the birefringence is minimized. Polarization fluctuation recorded a maximum of 180o during the 15 hour real time astronomer use of the antenna. To ascertain the contribution of the riser cable, state of polarization (SOP) of the buried section of the single mode fibre in the link was established. A maximum SOP change of 14o over 15 hour monitoring was measured. From the stability realized on the buried section of the fibre, the change in polarization is contributed by the riser cable. The fluctuation in polarization can cause the phase of a clock signal to drift between the birefringent axes by an equal amount corresponding to DGD. We experimentally demonstrate how polarization stabilization can be attained using the polarization maintaining fibre. We also demonstrate the applicability of VCSEL technology in the SKA unidirectional data flow especially for shorter baselines < 100 km. The VCSEL is a low cost light source with attractive advantages such as low power consumption, high speed capabilities and wavelength tuneability. This work entails the use of traditional amplitude modulation…
Subjects/Keywords: Optical communications; Fiber optics; Telecommunication systems
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2015). Fibre optic network supporting high speed transmission in the square kilometre array, South Africa. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/6552
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
author], [No. “Fibre optic network supporting high speed transmission in the square kilometre array, South Africa.” 2015. Thesis, Nelson Mandela Metropolitan University. Accessed January 16, 2021.
http://hdl.handle.net/10948/6552.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
author], [No. “Fibre optic network supporting high speed transmission in the square kilometre array, South Africa.” 2015. Web. 16 Jan 2021.
Vancouver:
author] [. Fibre optic network supporting high speed transmission in the square kilometre array, South Africa. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2015. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10948/6552.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
author] [. Fibre optic network supporting high speed transmission in the square kilometre array, South Africa. [Thesis]. Nelson Mandela Metropolitan University; 2015. Available from: http://hdl.handle.net/10948/6552
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
◁ [1] [2] [3] [4] [5] … [16] ▶
. 
Open Access Theses and Dissertations