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University of New Mexico
1.
Behzadi, Behsan.
NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS.
Degree: Optical Science and Engineering, 2018, University of New Mexico
URL: https://digitalrepository.unm.edu/ose_etds/62 
► The mid-infrared (2-14 μm) spectral region contains the strong absorption lines of many important molecular species, which make this region crucial for several well-know…
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▼ The mid-infrared (2-14 μm) spectral region contains the strong absorption lines of many important molecular species, which make this region crucial for several well-know applications such as spectroscopy, chemical and biochemical sensing, security, and industrial monitoring. To fully exploit this region through absorption spectroscopic techniques, compact and low-cost narrow-linewidth (NLW) mid-infrared (MIR) laser sources are of primary importance.
This thesis is focused on three novel compact NLW MIR lasers: demonstration and characterization of a new glass-based spherical microlaser, investigation of the performance of a novel fiber laser, and the design of a monolithic laser on a silicon chip. Starting with fabrication of spherical microcavities based on MIR transparent materials, I showed the feasibility of achieving quality factors of more than 10 million in whispering- gallery mode (WGM) microresonators made of different types of fluoride glasses. Next using Erbium doped ZBLAN glass spherical microresonators, I demonstrated a new ultra- low threshold NLW MIR microlaser. In particular, all aspects of this room temperature continuous-wave (CW) microlaser with a wavelength of 2.71 μm are carefully characterized and studied and the origin of the measured mode structure and polarization is described using a simple analysis. To amplify the output power of this laser, I designed and fabricated a MIR fiber amplifier with a record gain of about 30 dB at 2.71 μm that facilitated the characterization process and boosted the MIR power level to usable level while preserving the laser linewidth.
To demonstrate the application of MIR microresonators and microlasers, I studied intracavity absorption spectroscopy based on active and passive high quality WGM MIR microlasers and microresonators. I also estimated the sensitivity and detection limit of gas sensors based on these devices. The outcome of my analysis shows that ppm level sensitivity should be achievable using both active and passive microresonators.
Next, I modeled the performance of two newly proposed configurations for NLW MIR generation based on stimulated Raman scattering. First, I studied a new family of Raman fiber lasers that are capable of generating any NLW MIR line in the 2.5-9.5 μm spectral region. I demonstrated the feasibility of this MIR laser family, calculated the threshold conditions, identified the condition for its single-mode operation, and laid the foundation for the first experimental demonstration of such lasers. Finally, I explored the performance of silicon-based on-chip Raman lasers and the parameters that have prevented expanding their wavelength to MIR range. Using the outcomes of this study, I proposed and then analyzed a new architecture for on-chip silicon Raman lasers capable of generating single NLW lines around 3.2 μm with sub-mW threshold pump power.
Advisors/Committee Members: Mani Hossein-Zadeh, Ravinder K. Jain, Jean-Claude Diels, Ganesh Balakrishnan.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Behzadi, B. (2018). NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS. (Doctoral Dissertation). University of New Mexico. Retrieved from https://digitalrepository.unm.edu/ose_etds/62
Chicago Manual of Style (16th Edition):
Behzadi, Behsan. “NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS.” 2018. Doctoral Dissertation, University of New Mexico. Accessed February 22, 2020.
https://digitalrepository.unm.edu/ose_etds/62.
MLA Handbook (7th Edition):
Behzadi, Behsan. “NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS.” 2018. Web. 22 Feb 2020.
Vancouver:
Behzadi B. NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS. [Internet] [Doctoral dissertation]. University of New Mexico; 2018. [cited 2020 Feb 22].
Available from: https://digitalrepository.unm.edu/ose_etds/62.
Council of Science Editors:
Behzadi B. NOVEL COMPACT NARROW-LINEWIDTH MID-INFRARED LASERS FOR SENSING APPLICATIONS. [Doctoral Dissertation]. University of New Mexico; 2018. Available from: https://digitalrepository.unm.edu/ose_etds/62
2.
Chang, Hsieh-chi.
The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane.
Degree: MS, Electrical & Computer Engineering, 2012, University of Massachusetts
URL: https://scholarworks.umass.edu/theses/899
► The radiation quality factor of small vertically polarized antennas above a ground plane is investigated. Although the quality factor of small antennas in free…
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▼ The radiation quality factor of small vertically polarized antennas above a ground plane is investigated. Although the quality factor of small antennas in free space has been investigated extensively in the past, the exact effect of a conducting ground plane on the antenna bandwidth is not clearly understood. In this thesis, quality factors of vertically polarized antennas above a ground plane are computed and compared with their free-space counterparts. The theoretical results on quality factors are validated with simulations of electrically small spherical helix antennas.
Advisors/Committee Members: Do-Hoon Kwon.
Subjects/Keywords: Antennas; Electromagnetics and Photonics
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APA (6th Edition):
Chang, H. (2012). The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane. (Masters Thesis). University of Massachusetts. Retrieved from https://scholarworks.umass.edu/theses/899
Chicago Manual of Style (16th Edition):
Chang, Hsieh-chi. “The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane.” 2012. Masters Thesis, University of Massachusetts. Accessed February 22, 2020.
https://scholarworks.umass.edu/theses/899.
MLA Handbook (7th Edition):
Chang, Hsieh-chi. “The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane.” 2012. Web. 22 Feb 2020.
Vancouver:
Chang H. The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane. [Internet] [Masters thesis]. University of Massachusetts; 2012. [cited 2020 Feb 22].
Available from: https://scholarworks.umass.edu/theses/899.
Council of Science Editors:
Chang H. The Radiation Quality Factor Of Vertically Polarized Spherical Antennas Above A Conducting Ground Plane. [Masters Thesis]. University of Massachusetts; 2012. Available from: https://scholarworks.umass.edu/theses/899
Cal Poly
3.
Hempy, Alexander James.
Standalone Antenna Demonstration System.
Degree: MS, Electrical Engineering, 2010, Cal Poly
URL: https://digitalcommons.calpoly.edu/theses/319
;
10.15368/theses.2010.88
► Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications.…
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▼ Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill interest in the field of antenna design among high school and undergraduate college students. The system is portable, supplied solely by DC power supplies, easily reproducible, and includes rotational axes to illustrate antenna performance limitations and requirements. It provides a visual indication of wireless signal strength and demonstrates several antenna performance characteristics including polarization, gain and directivity, radiation patterns - nulls and maximums, and spreading loss. Several antenna types used in present-day applications (embedded and reflector antennas), in addition to structural barriers encountered in typical operating environments, are used to define wireless system performance. Students gain insight on radiating structure and orientation effects on antenna system characteristics and hopefully develop interest in future wireless studies.
Advisors/Committee Members: Dean Arakaki.
Subjects/Keywords: Antennas; Electromagnetics and Photonics
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APA (6th Edition):
Hempy, A. J. (2010). Standalone Antenna Demonstration System. (Masters Thesis). Cal Poly. Retrieved from https://digitalcommons.calpoly.edu/theses/319 ; 10.15368/theses.2010.88
Chicago Manual of Style (16th Edition):
Hempy, Alexander James. “Standalone Antenna Demonstration System.” 2010. Masters Thesis, Cal Poly. Accessed February 22, 2020.
https://digitalcommons.calpoly.edu/theses/319 ; 10.15368/theses.2010.88.
MLA Handbook (7th Edition):
Hempy, Alexander James. “Standalone Antenna Demonstration System.” 2010. Web. 22 Feb 2020.
Vancouver:
Hempy AJ. Standalone Antenna Demonstration System. [Internet] [Masters thesis]. Cal Poly; 2010. [cited 2020 Feb 22].
Available from: https://digitalcommons.calpoly.edu/theses/319 ; 10.15368/theses.2010.88.
Council of Science Editors:
Hempy AJ. Standalone Antenna Demonstration System. [Masters Thesis]. Cal Poly; 2010. Available from: https://digitalcommons.calpoly.edu/theses/319 ; 10.15368/theses.2010.88
College of William and Mary
4.
Smith, Kevin James.
Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet.
Degree: PhD, Physics, 2010, College of William and Mary
URL: https://scholarworks.wm.edu/etd/1539623568
► This thesis presents an investigation of the damping of spin waves in ferromagnetic Au(3 nm)/Ni(10 nm)/MgO(001) thin films using the time-resolved Magneto-optical Kerr Effect (TR-MOKE)…
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▼ This thesis presents an investigation of the damping of spin waves in ferromagnetic Au(3 nm)/Ni(10 nm)/MgO(001) thin films using the time-resolved Magneto-optical Kerr Effect (TR-MOKE) and ferromagnetic resonance (FMR) techniques. In the optical measurements, a 150 fs, 800 nm laser beam pulse is split into pump and probe components. The pump pulse, containing most of the beam energy, thermally excites coherent spin precession. The weaker probe pulse, time-delayed by a variable beam path, captures the magnetization dynamics via the polar MOKE effect, and oscillations are observed as a function of external field amplitude and direction. The extracted precession frequency is consistent in both the optical and resonance techniques; however, additional damping is observed in the TR-MOKE measurements that is strongly correlated to the orientation of the magnetization with respect to the magnetic anisotropy. The damping is identical in TR-MOKE and FMR only when the external field is applied near the easy axis of magnetization. The enhanced damping in TR-MOKE is shown to be a consequence of pump-induced inhomogeneous broadening in the presence of magnetic anisotropy, a result of differing temperature recovery profiles for the magnetization and magnetic anisotropy. Finally, a simple model is developed which explains the anisotropic damping: mode broadening occurs in regions where the magnetization changes rapidly with respect to changes in the external field, as determined by the curvature of the magnetic free energy. We thus introduce a novel damping effect in TR-MOKE: pump-induced anisotropic damping (PIAD).
Subjects/Keywords: Electromagnetics and Photonics; Physics
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APA (6th Edition):
Smith, K. J. (2010). Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet. (Doctoral Dissertation). College of William and Mary. Retrieved from https://scholarworks.wm.edu/etd/1539623568
Chicago Manual of Style (16th Edition):
Smith, Kevin James. “Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet.” 2010. Doctoral Dissertation, College of William and Mary. Accessed February 22, 2020.
https://scholarworks.wm.edu/etd/1539623568.
MLA Handbook (7th Edition):
Smith, Kevin James. “Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet.” 2010. Web. 22 Feb 2020.
Vancouver:
Smith KJ. Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet. [Internet] [Doctoral dissertation]. College of William and Mary; 2010. [cited 2020 Feb 22].
Available from: https://scholarworks.wm.edu/etd/1539623568.
Council of Science Editors:
Smith KJ. Optical control of ultrafast spin -wave relaxation by magnetic anisotropy in a ferromagnet. [Doctoral Dissertation]. College of William and Mary; 2010. Available from: https://scholarworks.wm.edu/etd/1539623568
University of Central Florida
5.
Klee, Anthony.
Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers.
Degree: 2016, University of Central Florida
URL: https://stars.library.ucf.edu/etd/4925
► Mode-locked lasers have numerous applications in the areas of communications, spectroscopy, and frequency metrology. Harmonically mode-locked semiconductor lasers with external ring cavities offer a unique…
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▼ Mode-locked lasers have numerous applications in the areas of communications, spectroscopy, and frequency metrology. Harmonically mode-locked semiconductor lasers with external ring cavities offer a unique combination of benefits in that they can produce high repetition rate pulse trains with low timing jitter, achieve narrow axial mode linewidths, have the potential for entire monolithic integration on-chip, feature high wall-plug efficiency due to direct electrical pumping, and can be engineered to operate in different wavelength bands of interest. However, lasers based on InP/InGaAsP quantum well devices which operate in the important telecom C-band have thus far been relatively limited in bandwidth as compared to competing platforms. Broad bandwidth is critical for increasing information carrying capacity and enabling femtosecond pulse production for coherent continuum generation in offset frequency stabilization. The goal of the work in this dissertation is to maximize the bandwidth of semiconductor lasers, bringing them closer to reaching their full potential as all-purpose sources.
Dispersion in the laser cavity is a primary limiter of the achievable bandwidth in the laser architectures covered in this dissertation. In the first part of this dissertation, an accurate self-referenced technique based on multi-heterodyne detection is developed for measuring the spectral phase of a mode-locked laser. This technique is used to characterize the dispersion in several semiconductor laser architectures. In the second part, this knowledge is applied to reduce the dispersion in a laser cavity using a programmable pulse shaper, and thus increase the laser's spectral bandwidth. We demonstrate a 10 GHz frequency comb with bandwidth spanning 5 THz, representing a twofold improvement over the previously achievable bandwidth. Finally, this laser is converted to a stand-alone system by reconfiguring it as a coupled opto-electronic oscillator and a novel stabilization scheme is presented.
Advisors/Committee Members: Delfyett, Peter.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Klee, A. (2016). Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/4925
Chicago Manual of Style (16th Edition):
Klee, Anthony. “Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers.” 2016. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/4925.
MLA Handbook (7th Edition):
Klee, Anthony. “Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers.” 2016. Web. 22 Feb 2020.
Vancouver:
Klee A. Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers. [Internet] [Doctoral dissertation]. University of Central Florida; 2016. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/4925.
Council of Science Editors:
Klee A. Broad Bandwidth Optical Frequency Combs from Low Noise, High Repetition Rate Semiconductor Mode-Locked Lasers. [Doctoral Dissertation]. University of Central Florida; 2016. Available from: https://stars.library.ucf.edu/etd/4925
University of Central Florida
6.
Mehta, Naman Anilkumar.
Multi-Purpose device for analyzing and measuring ultra-short pulses.
Degree: 2016, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5135
► Intensity auto correlator is device to measure pulse widths of ultrashort pulses on the order of picoseconds and femtoseconds. I have built an in-house, compact,…
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▼ Intensity auto correlator is device to measure pulse widths of ultrashort pulses on the order of picoseconds and femtoseconds. I have built an in-house, compact, portable, industry standard intensity auto correlator for measuring ultrashort pulse-widths. My device is suitable for pulse-widths from 500 ps to 50 fs. The impetus for developing this instrument stemmed from our development of a multicore-fiber laser for high power laser applications, which also produces very short pulses that cannot be measured with an oscilloscope. As techniques for measuring short pulse-widths have been well studied, what made my journey exciting was the process of taking an idea and realizing a successful, cost-efficient device. In this study, I have analyzed a Q-switched laser and my measured pulse-width matched the theoretical value previously calculated. I have also analyzed our mode-locked multicore fiber laser and results were encouraging. The notion to build one intensity autocorrelator was based on our labs future work, which was with modelocked multicore fiber laser, which at the moment is giving pulses on order of nanoseconds. Dr. Axel Schulzgen gave the responsibility to build an intensity autocorrelator on my shoulders. As, Intensity autocorrelators have been around for long time, he encouraged me to make one in house, compact, portable intensity autocorrelator which measures pulse widths of 50 fs up to 500 ps quite easily.
Advisors/Committee Members: Schulzgen, Axel.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Mehta, N. A. (2016). Multi-Purpose device for analyzing and measuring ultra-short pulses. (Masters Thesis). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5135
Chicago Manual of Style (16th Edition):
Mehta, Naman Anilkumar. “Multi-Purpose device for analyzing and measuring ultra-short pulses.” 2016. Masters Thesis, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5135.
MLA Handbook (7th Edition):
Mehta, Naman Anilkumar. “Multi-Purpose device for analyzing and measuring ultra-short pulses.” 2016. Web. 22 Feb 2020.
Vancouver:
Mehta NA. Multi-Purpose device for analyzing and measuring ultra-short pulses. [Internet] [Masters thesis]. University of Central Florida; 2016. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5135.
Council of Science Editors:
Mehta NA. Multi-Purpose device for analyzing and measuring ultra-short pulses. [Masters Thesis]. University of Central Florida; 2016. Available from: https://stars.library.ucf.edu/etd/5135
University of Central Florida
7.
Kagalwala, Kumel.
Entanglement and Coherence in Classical and Quantum Optics.
Degree: 2015, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5150
► We explore the concepts of coherence and entanglement as they apply to both the classical and quantum natures of light. In the classical domain,…
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▼ We explore the concepts of coherence and entanglement as they apply to both the classical and quantum natures of light. In the classical domain, we take inspiration from the tools and concepts developed in foundational quantum mechanics and quantum information science to gain a better understanding of classical coherence theory of light with multiple degrees of freedom (DoFs). First, we use polarization and spatial parity DoFs to demonstrate the notion of classical entanglement, and show that Bell's measure can serve as a useful tool in distinguishing between classical optical coherence theory. Second, we establish a methodical yet versatile approach called 'optical coherency matrix tomography' for reconstructing the coherency matrix of an electromagnetic beam with multiple DoFs. This technique exploits the analogy between this problem in classical optics and that of tomographically reconstructing the density matrix associated with multipartite quantum states in quantum information science. Third, we report the first experimental measurements of the 4 x 4 coherency matrix associated with an electromagnetic beam in which polarization and a spatial DoF are relevant, ranging from the traditional two-point Young's double slit to spatial parity and orbital angular momentum modes. In the quantum domain, we use the modal structure of classical fields to develop qubits and structure Hilbert spaces for use in quantum information processing. Advancing to three-qubit logic gates is an important step towards the success of optical schemes for quantum computing. We experimentally implement a variety of two- and three- qubit, linear and deterministic, single-photon, controlled, quantum logic gates using polarization and spatial parity qubits. Lastly, we demonstrate the implementation of two-qubit single-photon logic using polarization and orbital angular momentum qubits.
Advisors/Committee Members: Saleh, Bahaa.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Kagalwala, K. (2015). Entanglement and Coherence in Classical and Quantum Optics. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5150
Chicago Manual of Style (16th Edition):
Kagalwala, Kumel. “Entanglement and Coherence in Classical and Quantum Optics.” 2015. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5150.
MLA Handbook (7th Edition):
Kagalwala, Kumel. “Entanglement and Coherence in Classical and Quantum Optics.” 2015. Web. 22 Feb 2020.
Vancouver:
Kagalwala K. Entanglement and Coherence in Classical and Quantum Optics. [Internet] [Doctoral dissertation]. University of Central Florida; 2015. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5150.
Council of Science Editors:
Kagalwala K. Entanglement and Coherence in Classical and Quantum Optics. [Doctoral Dissertation]. University of Central Florida; 2015. Available from: https://stars.library.ucf.edu/etd/5150
University of Central Florida
8.
Rao, Ashutosh.
Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon.
Degree: 2018, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5836
► Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over…
(more)
▼ Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated
photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First, two types of compact electrooptic modulators are presented – microring modulators, and Mach-Zehnder modulators. Next, two distinct approaches to nonlinear optical frequency converters are implemented – periodically poled lithium niobate, and mode shape modulation (grating assisted quasi-phase matching). Following this, stochastic variations are added to the mode shape modulation approach to demonstrate random quasi-phase matching. Afterward, broadband photon-pair generation is demonstrated in the miniaturized periodically poled lithium niobate, and spectral correlations of the biphoton spectrum are reported. Finally, extensions of the aforementioned results suitable for future work are discussed.
Advisors/Committee Members: Fathpour, Sasan.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Rao, A. (2018). Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5836
Chicago Manual of Style (16th Edition):
Rao, Ashutosh. “Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon.” 2018. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5836.
MLA Handbook (7th Edition):
Rao, Ashutosh. “Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon.” 2018. Web. 22 Feb 2020.
Vancouver:
Rao A. Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon. [Internet] [Doctoral dissertation]. University of Central Florida; 2018. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5836.
Council of Science Editors:
Rao A. Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon. [Doctoral Dissertation]. University of Central Florida; 2018. Available from: https://stars.library.ucf.edu/etd/5836
University of Central Florida
9.
Xu, Daming.
Advanced Blue Phase Liquid Crystal Displays.
Degree: 2016, University of Central Florida
URL: https://stars.library.ucf.edu/etd/4926
► Thin-film transistor (TFT) liquid crystal displays (LCDs) have become indispensable in our daily lives. Their widespread applications range from smartphones, laptops, TVs to navigational devices,…
(more)
▼ Thin-film transistor (TFT) liquid crystal displays (LCDs) have become indispensable in our daily lives. Their widespread applications range from smartphones, laptops, TVs to navigational devices, data projectors and wearable displays. Over past decades, massive efforts have been invested in device development, material characterization and manufacturing technology. As a result, the performance of LCDs, such as viewing angle, contrast ratio, color gamut and resolution, have been improved significantly. Nonetheless, there are still urgent needs for fast response time and low power consumption. Fast response time helps reduce motion image blurs and enable color sequential displays. The latter is particularly attractive since it eliminates spatial color filters, which in turn triples optical efficiency and resolution density. The power consumption can be reduced greatly by using color sequential displays, but liquid crystals with submillisecond response time are required to minimize color breakup. The state-of-the-art gray-to-gray response time of nematic LCDs is about 5ms, which is too slow to meet this requirement.
With the urgent needs for submillisecond response time, polymer-stabilized blue phase liquid crystal is emerging as a strong candidate for achieving this goal. Compared to conventional nematic LCDs, blue phase LCDs exhibit several revolutionary features: submillisecond gray-to-gray response time, no need for alignment layer, optically isotropic voltage-off state, and large cell gap tolerance. However, some bottlenecks such as high operation voltage, low optical transmittance, noticeable hysteresis and slow TFT charging remain to be overcome before their widespread applications can be realized. This dissertation is dedicated to addressing these challenges from material development and device design viewpoints.
First, we started to investigate the device physics of blue phase LCDs. We have built a numerical model based on the refraction effect for simulating the electro-optics of blue phase devices. The model well agrees with experimental data. Based on this model, we explored approaches from device and material viewpoints to achieve low operation voltage. On the device side, with protrusion and etched electrodes, we can reduce the operating voltage to below 10V and enhance the transmittance to over 80%. On the material side, high Kerr constant is indeed helpful for lowering the operation voltage, but we also need to pay attention to the individual ?n and ?? values of liquid crystal host according to the device structures employed. High-?? LC hosts help enhance Kerr constant, leading to a reduced operation voltage; but they may be
subject to serious capacitance charging issues due to the huge dielectric anisotropy. Our model provides important guidelines for future device design and material development.
To further enhance transmittance and reduce voltage, we have proposed a Z-shaped electrode structure. By optimizing the device structure, we have successfully reduced the operating voltage to ~8V and enhanced…
Advisors/Committee Members: Wu, Shin-Tson.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA ·
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APA (6th Edition):
Xu, D. (2016). Advanced Blue Phase Liquid Crystal Displays. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/4926
Chicago Manual of Style (16th Edition):
Xu, Daming. “Advanced Blue Phase Liquid Crystal Displays.” 2016. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/4926.
MLA Handbook (7th Edition):
Xu, Daming. “Advanced Blue Phase Liquid Crystal Displays.” 2016. Web. 22 Feb 2020.
Vancouver:
Xu D. Advanced Blue Phase Liquid Crystal Displays. [Internet] [Doctoral dissertation]. University of Central Florida; 2016. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/4926.
Council of Science Editors:
Xu D. Advanced Blue Phase Liquid Crystal Displays. [Doctoral Dissertation]. University of Central Florida; 2016. Available from: https://stars.library.ucf.edu/etd/4926
University of Central Florida
10.
Ulhassan, Absar.
Non-Hermitian Optics.
Degree: 2018, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6011
► From the viewpoint of quantum mechanics, a system must always be Hermitian since all its corresponding eigenvalues must be real. In contrast, the eigenvalues of…
(more)
▼ From the viewpoint of quantum mechanics, a system must always be Hermitian since all its corresponding eigenvalues must be real. In contrast, the eigenvalues of open systems-unrestrained because of either decay or amplification-can be in general complex. Not so long ago, a certain class of non-Hermitian Hamiltonians was discovered that could have a completely real eigenvalue spectrum. This special class of Hamiltonians was found to respect the property of commutation with the parity-time (PT) operator. Translated into optics, this implies a balance between regions exhibiting gain and loss. Traditionally, loss has been perceived as a foe in optics and something that needs to be avoided at all costs. As we will show, when used in conjunction with gain, the presence of loss can lead to a host of counterintuitive outcomes in such non-Hermitian configurations that would have been otherwise unattainable in standard arrangements. We will study PT symmetric phase transitions in various optical settings that include semiconductor microrings and coupled fiber cavities, and show how they can allow mode-selectivity in lasers. One of the key outcomes of this effort was the realization of higher order degeneracies in a three-cavity laser configuration that can exhibit orders-of-magnitude larger sensitivity to external perturbations. We will also consider systems that display nonlinear effects such as gain saturation, thus allowing novel phase transitions. Some interesting properties associated with degeneracies in non-Hermitian settings will be investigated as well. Such degeneracies, called exceptional points (EPs), are much more drastic compared to standard degeneracies of eigenvalues because the corresponding eigenvectors also coalesce, which in turn reduces the dimensionality of the phase space. We will show that dynamic parameter contours enclosing or close to EPs can lead to a robust chiral mode conversion process – something that can be potentially used to realize omni-polarizing optical devices.
Advisors/Committee Members: Christodoulides, Demetrios.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Ulhassan, A. (2018). Non-Hermitian Optics. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6011
Chicago Manual of Style (16th Edition):
Ulhassan, Absar. “Non-Hermitian Optics.” 2018. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6011.
MLA Handbook (7th Edition):
Ulhassan, Absar. “Non-Hermitian Optics.” 2018. Web. 22 Feb 2020.
Vancouver:
Ulhassan A. Non-Hermitian Optics. [Internet] [Doctoral dissertation]. University of Central Florida; 2018. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6011.
Council of Science Editors:
Ulhassan A. Non-Hermitian Optics. [Doctoral Dissertation]. University of Central Florida; 2018. Available from: https://stars.library.ucf.edu/etd/6011
University of Central Florida
11.
Akhlaghi Bouzan, Milad.
Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing.
Degree: 2017, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6090
► Properties of light such as amplitude and phase, temporal and spatial coherence, polarization, etc. are abundantly used for sensing and imaging. Regardless of the passive…
(more)
▼ Properties of light such as amplitude and phase, temporal and spatial coherence, polarization, etc. are abundantly used for sensing and imaging. Regardless of the passive or active nature of the sensing method, optical intensity fluctuations are always present! While these fluctuations are usually regarded as noise, there are situations where one can harness the intensity fluctuations to enhance certain attributes of the sensing procedure. In this thesis, we developed different sensing methodologies that use statistical properties of optical fluctuations for gauging specific information. We examine this concept in the context of three different aspects of computational optical imaging and sensing. First, we study imposing specific statistical properties to the probing field to image or characterize certain properties of an object through a statistical analysis of the spatially integrated scattered intensity. This offers unique capabilities for imaging and sensing techniques operating in highly perturbed environments and low-light conditions. Next, we examine optical sensing in the presence of strong perturbations that preclude any controllable field modification. We demonstrate that inherent properties of diffused coherent fields and fluctuations of integrated intensity can be used to track objects hidden behind obscurants. Finally, we address situations where, due to coherent noise, image accuracy is severely degraded by intensity fluctuations. By taking advantage of the spatial coherence properties of optical fields, we show that this limitation can be effectively mitigated and that a significant improvement in the signal-to-noise ratio can be achieved even in one single-shot measurement. The findings included in this dissertation illustrate different circumstances where optical fluctuations can affect the efficacy of computational optical imaging and sensing. A broad range of applications, including biomedical imaging and remote sensing, could benefit from the new approaches to suppress, enhance, and exploit optical fluctuations, which are described in this dissertation.
Advisors/Committee Members: Dogariu, Aristide.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Akhlaghi Bouzan, M. (2017). Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6090
Chicago Manual of Style (16th Edition):
Akhlaghi Bouzan, Milad. “Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing.” 2017. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6090.
MLA Handbook (7th Edition):
Akhlaghi Bouzan, Milad. “Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing.” 2017. Web. 22 Feb 2020.
Vancouver:
Akhlaghi Bouzan M. Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing. [Internet] [Doctoral dissertation]. University of Central Florida; 2017. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6090.
Council of Science Editors:
Akhlaghi Bouzan M. Harnessing Spatial Intensity Fluctuations for Optical Imaging and Sensing. [Doctoral Dissertation]. University of Central Florida; 2017. Available from: https://stars.library.ucf.edu/etd/6090
University of Central Florida
12.
Wang, Yang.
Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments.
Degree: 2017, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5760
► At present, the energy of a single isolated attosecond pulse is limited to nanojoule levels. As a result, an intense femtosecond pulse has always…
(more)
▼ At present, the energy of a single isolated attosecond pulse is limited to nanojoule levels. As a result, an intense femtosecond pulse has always been used in combination with a weak attosecond pulse in time-resolved experiments. To reach the goal of conducting true attosecond pump-attosecond probe experiments, a high flux laser source has been developed that can potentially deliver microjoule level isolated attosecond pulses in the 50 eV range, and a unique experimental end station has been fabricated and implemented that can provide precision control of the attosecond-attosecond pump-probe pulses. In order to scale up the attosecond flux, a unique Ti:-Sapphire laser system with a three-stage amplifier that delivers pulses with a 2 J energy at a 10 Hz repetition rate was designed and built. The broadband pulse spectrum covering from 700 nm to 900 nm was generated, supporting a pulse duration of 12 fs. The high flux high-order harmonics were generated in a gas tube filled with argon by a loosely focused geometry under a phase-matching condition. The wavefront distortions for the driving laser were corrected by a deformable mirror with a Shack-Hartmann sensor to significantly improve the extreme ultraviolet radiation conversion efficiency due to the excellent beam profile at focus. A high-damage-threshold beam splitter is demonstrated to eliminate energetic driving laser pulses from high-order harmonics. The extreme ultraviolet pulse energy is measured to be 0.3 microjoule at the exit of the argon gas target. The experimental facilities developed will lead to the generation of microjoule level isolated attosecond pulses and the demonstration of true atto pump-atto probe experiments in near future. Finally, in experiment, we show the first demonstration of carrier-envelope phase controlled filamentation in air using millijoule-level few-cycle mid-infrared laser pulses.
Advisors/Committee Members: Chang, Zenghu.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Wang, Y. (2017). Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5760
Chicago Manual of Style (16th Edition):
Wang, Yang. “Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments.” 2017. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5760.
MLA Handbook (7th Edition):
Wang, Yang. “Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments.” 2017. Web. 22 Feb 2020.
Vancouver:
Wang Y. Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments. [Internet] [Doctoral dissertation]. University of Central Florida; 2017. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5760.
Council of Science Editors:
Wang Y. Generation of High-Flux Attosecond Pulses and Towards Attosecond-Attosecond Pump-Probe Experiments. [Doctoral Dissertation]. University of Central Florida; 2017. Available from: https://stars.library.ucf.edu/etd/5760
University of Central Florida
13.
Eftekhar, Mohammad Amin.
Nonlinear Dynamics in Multimode Optical Fibers.
Degree: 2018, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6215
► Multimode optical fibers have recently reemerged as a viable platform for addressing a number of long-standing issues associated with information bandwidth requirements and power-handling capabilities.…
(more)
▼ Multimode optical fibers have recently reemerged as a viable platform for addressing a number of long-standing issues associated with information bandwidth requirements and power-handling capabilities. The complex nature of heavily multimoded systems can be effectively exploited to observe altogether novel physical effects arising from spatiotemporal and intermodal linear and nonlinear processes. Here, we have studied nonlinear dynamics in multimode optical fibers (MMFs) in both the normal and anomalous dispersion regimes. In the anomalous dispersion regime, the nonlinearity leads to a formation of spatiotemporal 3-D solitons. Unlike in single-mode fibers, these solitons are not unique and their properties can be modified through the additional degrees of freedom offered by these multimoded settings. In addition, soliton related processes such as soliton fission and dispersive wave generation will be also drastically altered in such multimode systems. Our theoretical work unravels some of the complexities of the underlying dynamics and helps us better understand these effects. The nonlinear dynamics in such multimode systems can be accelerated through a judicious fiber design. A cancelation of Raman self-frequency shifts and Blue-shifting multimode solitons were observed in such settings as a result of an acceleration of intermodal oscillations. Spatiotemporal instabilities in parabolic-index multimode fibers will also be discussed. In the normal dispersion regime, this effect can be exploited to generate an ultrabroad and uniform supercontinuum that extends more than 2.5 octaves. To do so, the unstable spectral regions are pushed away from the pump, thus sweeping the entire spectrum. Multimode parabolic pulses were also predicted and observed in passive normally dispersive tapered MMFs. These setting can obviate the harsh bandwidth limitation present in single-mode system imposed by gain medium and be effectively used for realizing high power multimode fiber lasers. Finally, an instant and efficient second-harmonic generation was observed in the multimode optical fibers. Through a modification of initial conditions, the efficiency of this process could be enhanced to a record high of %6.5.
Advisors/Committee Members: Christodoulides, Demetrios.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Eftekhar, M. A. (2018). Nonlinear Dynamics in Multimode Optical Fibers. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6215
Chicago Manual of Style (16th Edition):
Eftekhar, Mohammad Amin. “Nonlinear Dynamics in Multimode Optical Fibers.” 2018. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6215.
MLA Handbook (7th Edition):
Eftekhar, Mohammad Amin. “Nonlinear Dynamics in Multimode Optical Fibers.” 2018. Web. 22 Feb 2020.
Vancouver:
Eftekhar MA. Nonlinear Dynamics in Multimode Optical Fibers. [Internet] [Doctoral dissertation]. University of Central Florida; 2018. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6215.
Council of Science Editors:
Eftekhar MA. Nonlinear Dynamics in Multimode Optical Fibers. [Doctoral Dissertation]. University of Central Florida; 2018. Available from: https://stars.library.ucf.edu/etd/6215
University of Central Florida
14.
Hodaei, Hossein.
Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points.
Degree: 2017, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5740
► In recent years, non-Hermitian degeneracies also known as exceptional points (EPs) have emerged as a new paradigm for engineering the response of optical systems.…
(more)
▼ In recent years, non-Hermitian degeneracies also known as exceptional points (EPs) have emerged as a new paradigm for engineering the response of optical systems. EPs can appear in a wide class of open non-Hermitian configurations. Among different types of non-conservative photonic systems, parity-time (PT) symmetric arrangements are of particular interest since they provide an excellent platform to explore the physics of exceptional points. In this work, the intriguing properties of exceptional points are utilized to address two of the long standing challenges in the field of integrated
photonics- enforcing single mode lasing in intrinsically multimode cavities and enhancing the sensitivity of micro-resonators. In the first part of this work, I will describe how stable single mode lasing can be readily achieved in longitudinally and transversely multi-moded microring cavities through the systematic utilization of abrupt phase transitions at exceptional points. This technique will be first demonstrated in a parity-time laser that is comprised of a gain cavity coupled to an identical but lossy counterpart. A detailed study of the behavior of this system around the exceptional point will be presented. Furthermore, we report the first experimental realization of a dark state laser in which by strategically designing the spectral locations of exceptional points, widely tunable single-mode lasing can be attained even at high pump levels. Despite the presence of loss in such open laser systems, the slope efficiency remains virtually intact. Our results demonstrate the potential of exceptional points as a versatile design tool for mode management in on-chip laser configurations. In the second part of my dissertation, I will show how the exceptional points and their underlying degeneracies can be used to significantly boost the intrinsic sensitivity of microcavities. I will demonstrate the enhanced sensitivity in a binary PT-symmetric coupled cavity arrangement that is biased at an exceptional point. Then I will report the first observation of higher-order exceptional points in a ternary parity-time symmetric microring laser system with a judiciously tailored gain-loss distribution. The enhanced response associated with this ternary system follows a cubic root dependence on externally introduced perturbation, which can in turn be detected in the spectral domain. Using such arrangements, more than one order of magnitude enhancement in the sensitivity is observed experimentally. These results can pave the way towards improving the performance of current on-chip micro-cavity sensors.
Advisors/Committee Members: Khajavikhan, Mercedeh.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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MLA ·
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APA (6th Edition):
Hodaei, H. (2017). Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5740
Chicago Manual of Style (16th Edition):
Hodaei, Hossein. “Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points.” 2017. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5740.
MLA Handbook (7th Edition):
Hodaei, Hossein. “Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points.” 2017. Web. 22 Feb 2020.
Vancouver:
Hodaei H. Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points. [Internet] [Doctoral dissertation]. University of Central Florida; 2017. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5740.
Council of Science Editors:
Hodaei H. Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points. [Doctoral Dissertation]. University of Central Florida; 2017. Available from: https://stars.library.ucf.edu/etd/5740
University of Central Florida
15.
Li, Jie.
Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime.
Degree: 2018, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5835
► The observation of any atomic and molecular dynamics requires a probe that has a timescale comparable to the dynamics itself. Ever since the invention of…
(more)
▼ The observation of any atomic and molecular dynamics requires a probe that has a timescale comparable to the dynamics itself. Ever since the invention of laser, the temporal duration of the laser pulse has been incrementally reduced from several nanoseconds to just attoseconds. Picosecond and femtosecond laser pulses have been widely used to study molecular rotation and vibration.
In 2001, the first single isolated attosecond pulse (1 attosecond = 10^-18 seconds.) was demonstrated. Since this breakthrough, "attoscience" has become a hot topic in ultrafast physics. Attosecond pulses typically have span between EUV to X-ray photon energies and sub-femtosecond pulse duration. It becomes an ideal tool for experimentalists to study ultrafast electron dynamics in atoms, molecules and condensed matter.
The conventional scheme for generating attosecond pulses is focusing an intense femtosecond laser pulse into inert gases. The bound electrons are ionized into continuum through tunneling ionization under the strong electrical field. After ionization, the free electron will be accelerated by the laser field away from the parent ion and then recombined with its parent ion and releases its kinetic energy as a photon burst that lasts for a few hundred attoseconds. According to the classical "three-step model", high order harmonic will have a higher cutoff photon energy when driven by a longer wavelength laser field. Compared to Ti:sapphire lasers center at a wavelength of 800 nm, an optical parametric amplifier could offer a broad bandwidth at infrared range, which could support few cycle pulses for driving high harmonic generation in the X-ray spectrum range.
In this work, an optical parametric chirped-pulse amplification system was developed to deliver CEP-stable 3-mJ, 12-fs pulses centered at 1.7 micron. We implement a chirped-pump technique to phase match the board parametric amplification bandwidth with high conversion efficiency. Using such a laser source, isolated attosecond pulses with photon exceeding 300 eV are achieved by applying the polarization gating technique at 1.7 micron. The intrinsic positive chirp of the attosecond pulses is measured by the attosecond streak camera and retrieved with our PROOF technique. Sn metal filters with negative dispersion were chosen to compensate the intrinsic attochirp. As a result, isolated 53-attosecond soft x-ray pulses are achieved. Such water window attosecond source will be a powerful tool for studying charge distribution/migration in bio-molecules and will bring opportunities to study high field physics or attochemistry.
Advisors/Committee Members: Chang, Zenghu.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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MLA ·
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APA (6th Edition):
Li, J. (2018). Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5835
Chicago Manual of Style (16th Edition):
Li, Jie. “Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime.” 2018. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5835.
MLA Handbook (7th Edition):
Li, Jie. “Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime.” 2018. Web. 22 Feb 2020.
Vancouver:
Li J. Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime. [Internet] [Doctoral dissertation]. University of Central Florida; 2018. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5835.
Council of Science Editors:
Li J. Generation and Characterization of Isolated Attosecond Pulse in the Soft X-ray Regime. [Doctoral Dissertation]. University of Central Florida; 2018. Available from: https://stars.library.ucf.edu/etd/5835
University of Central Florida
16.
Chen, Haiwei.
Advanced liquid crystal displays with supreme image qualities.
Degree: 2017, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5698
► Several metrics are commonly used to evaluate the performance of display devices. In this dissertation, we analyze three key parameters: fast response time, wide color…
(more)
▼ Several metrics are commonly used to evaluate the performance of display devices. In this dissertation, we analyze three key parameters: fast response time, wide color gamut, and high contrast ratio, which affect the final perceived image quality. Firstly, we investigate how response time affects the motion blur, and then discover the 2-ms rule. With advanced low-viscosity materials, new operation modes, and backlight modulation technique, liquid crystal displays (LCDs) with an unnoticeable image blur can be realized. Its performance is comparable to an impulse-type display, like cathode ray tube (CRT). Next, we propose two novel backlight configurations to improve an LCD's color gamut. One is to use a functional reflective polarizer (FRP), acting as a notch filter to block the unwanted light, and the other is to combine FRP with a patterned half-wave plate to suppress the crosstalk between blue and green/red lights. In experiment, we achieved 97.3% Rec. 2020 in CIE 1976 color space, which is approaching the color gamut of a laser projector. Finally, to enhance an LCD's contrast ratio, we proposed a novel device configuration by adding an in-cell polarizer between LC layer and color filter array. The CR for a vertically-aligned LCD is improved from 5000:1 to 20,000:1, and the CR for a fringe field switching LCD is improved from 2000:1 to over 3000:1. To further enlarge CR to fulfill the high dynamic range requirement, a dual-panel LCD system is proposed and the measured contrast ratio exceeds 1,000,000:1. Overall speaking, such an innovated LCD exhibits supreme image qualities with motion picture response time comparable to CRT, vivid color to laser projector, and contrast ratio to OLED. Along with other outstanding features, like high peak brightness, high resolution density, long lifetime, and low cost, LCD would continue to maintain its dominance in consumer electronics in the foreseeable future.
Advisors/Committee Members: Wu, Shin-Tson.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA ·
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APA (6th Edition):
Chen, H. (2017). Advanced liquid crystal displays with supreme image qualities. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5698
Chicago Manual of Style (16th Edition):
Chen, Haiwei. “Advanced liquid crystal displays with supreme image qualities.” 2017. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5698.
MLA Handbook (7th Edition):
Chen, Haiwei. “Advanced liquid crystal displays with supreme image qualities.” 2017. Web. 22 Feb 2020.
Vancouver:
Chen H. Advanced liquid crystal displays with supreme image qualities. [Internet] [Doctoral dissertation]. University of Central Florida; 2017. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5698.
Council of Science Editors:
Chen H. Advanced liquid crystal displays with supreme image qualities. [Doctoral Dissertation]. University of Central Florida; 2017. Available from: https://stars.library.ucf.edu/etd/5698
University of Central Florida
17.
Luo, Zhenyue.
High Efficiency and Wide Color Gamut Liquid Crystal Displays.
Degree: 2015, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5017
► Liquid crystal display (LCD) has become ubiquitous and indispensable in our daily life. Recently, it faces strong competition from organic light emitting diode (OLED).…
(more)
▼ Liquid crystal display (LCD) has become ubiquitous and indispensable in our daily life. Recently, it faces strong competition from organic light emitting diode (OLED). In order to maintain a strong leader position, LCD camp has an urgent need to enrich the color performance and reduce the power consumption. This dissertation focuses on solving these two emerging and important challenges. In the first part of the dissertation we investigate the quantum dot (QD) technology to improve the both the color gamut and the light efficiency of LCD. QD emits saturated color and grants LCD the capability to reproduce color vivid images. Moreover, the QD emission spectrum can be custom designed to match to transmission band of color filters. To fully take advantage of QD’s unique features, we propose a systematic modelling of the LCD backlight and optimize the QD spectrum to simultaneously maximize the color gamut and light efficiency. Moreover, QD enhanced LCD demonstrates several advantages: excellent ambient contrast, negligible color shift and controllable white point. Besides three primary LCD, We also present a spatiotemporal four-primary QD enhanced LCD. The LCD’s color is generated partially from time domain and partially from spatial domain. As a result, this LCD mode offers 1.5× increment in spatial resolution, 2× brightness enhancement, slightly larger color gamut and mitigated LC response requirement (~4ms). It can be employed in the commercial TV to meet the challenging Energy star 6 regulation. Besides conventional LCD, we also extend the QD applications to liquid displays and smart lighting devices. The second part of this dissertation focuses on improving the LCD light efficiency. Conventional LCD system has fairly low light efficiency (4%~7%) since polarizers and color filters absorb 50% and 67% of the incoming light respectively. We propose two approaches to reduce the light loss within polarizers and color filters. The first method is a polarization preserving backlight system. It can be combined with linearly polarized light source to boost the LCD efficiency. Moreover, this polarization preserving backlight offers high polarization efficiency (~77.8%), 2.4× on-axis luminance enhancement, and no need for extra optics films. The second approach is a LCD backlight system with simultaneous color/polarization recycling. We design a novel polarizing color filter with high transmittance (>90%), low absorption loss (~3.3%), high extinction ratio (>10,000:1) and large angular tolerance (up to ±50˚). This polarizing color filter can be used in LCD system to introduce the color/polarization recycling and accordingly boost LCD efficiency by ~3 times. These two approaches open new gateway for ultra-low power LCDs. In the final session of this dissertation, we demonstrate a low power and color vivid reflective liquid crystal on silicon (LCOS) display with low viscosity liquid crystal mixture. Compared with commercial LC material, the new LC mixture offers ~4X faster response at 20 °C and ~8X faster response at -20 °C.…
Advisors/Committee Members: Wu, Shin-Tson.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA ·
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MLA ·
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Export
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Manager
APA (6th Edition):
Luo, Z. (2015). High Efficiency and Wide Color Gamut Liquid Crystal Displays. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5017
Chicago Manual of Style (16th Edition):
Luo, Zhenyue. “High Efficiency and Wide Color Gamut Liquid Crystal Displays.” 2015. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5017.
MLA Handbook (7th Edition):
Luo, Zhenyue. “High Efficiency and Wide Color Gamut Liquid Crystal Displays.” 2015. Web. 22 Feb 2020.
Vancouver:
Luo Z. High Efficiency and Wide Color Gamut Liquid Crystal Displays. [Internet] [Doctoral dissertation]. University of Central Florida; 2015. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5017.
Council of Science Editors:
Luo Z. High Efficiency and Wide Color Gamut Liquid Crystal Displays. [Doctoral Dissertation]. University of Central Florida; 2015. Available from: https://stars.library.ucf.edu/etd/5017
University of Central Florida
18.
Malinowski, Marcin.
Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6526
► The field of integrated photonics aims at compressing large and environmentally-sensitive optical systems to micron-sized circuits that can be mass-produced through existing semiconductor fabrication facilities.…
(more)
▼ The field of integrated
photonics aims at compressing large and environmentally-sensitive optical systems to micron-sized circuits that can be mass-produced through existing semiconductor fabrication facilities. The integration of optical components on single chips is pivotal to the realization of miniature systems with high degree of complexity. Such novel photonic chips find abundant applications in optical communication, spectroscopy and signal processing. This work concentrates on harnessing nonlinear phenomena to this avail.
The first part of this dissertation discusses, both from component and system level, the development of a frequency comb source with a semiconductor mode-locked laser at its heart. New nonlinear devices for supercontinuum and second-harmonic generations are developed and their performance is assessed inside the system. Theoretical analysis of a hybrid approach with synchronously-pumped Kerr cavity is also provided. The second part of the dissertation investigates stimulated Brillouin scattering (SBS) in integrated
photonics. A fully-tensorial open-source numerical tool is developed to study SBS in optical waveguides composed of crystalline materials, particularly silicon. SBS is demonstrated in an all-silicon optical platform.
Advisors/Committee Members: Fathpour, Sasan.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Malinowski, M. (2019). Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6526
Chicago Manual of Style (16th Edition):
Malinowski, Marcin. “Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6526.
MLA Handbook (7th Edition):
Malinowski, Marcin. “Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications.” 2019. Web. 22 Feb 2020.
Vancouver:
Malinowski M. Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6526.
Council of Science Editors:
Malinowski M. Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6526
University of Central Florida
19.
Ru, Qitian.
Broadband Mid-infrared Frequency Combs Generated via Frequency Division.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6570
► Frequency combs have revolutionized metrology and demonstrated numerous applications in science and technology. Combs operating in the mid-infrared region could be beneficial for molecular spectroscopy…
(more)
▼ Frequency combs have revolutionized metrology and demonstrated numerous applications in science and technology. Combs operating in the mid-infrared region could be beneficial for molecular spectroscopy for several reasons. First, numerous molecules have their spectroscopic signatures in this region. Furthermore, the atmospheric window (3-5μm and 8-14μm) is located here. Additionally, a mid-infrared frequency comb could be employed as a diagnostic tool for the many components of human breath, as well as for detection of harmful gases and contaminants in the atmosphere. In this thesis, I used synchronously pumped subharmonic optical parametric oscillators (OPOs) operating at degeneracy to produce ultra-broadband outputs near half of the pump laser frequency. One attractive property of the subharmonic OPOs is that the signal/idler waves of the OPO are frequency- and phase-locked to the pump frequency comb. We explored three new nonlinear materials in the subharmonic OPO and demonstrated a broadband spectrum for mid-infrared frequency comb generation. (1) Orientation-patterned (OP) gallium arsenide (GaAs) was selected as the first material because it has high nonlinearity. We found that the OP-GaAs based OPO yielded an approximately two-octave wide spectrum (2.8–11μm). (2) Gallium phosphide (GaP) has near zero group velocity dispersion (GVD) at 4.7 μm and a large bandgap. The OP-GaP OPO yielded a spectrum of more than two octaves (3–12.5μm). Also, because of the large bandgap, GaP is suitable for telecom 1.56-μm pumping, having the advantage of much smaller GVD than in periodically-poled-lithium-niobite (PPLN). The telecom laser (1.56μm) pumped OP-GaP OPO was demonstrated with more than one octave wide spectrum. (3) Finally, we explored the phenomenon of random phase matching in the zinc selenide (ZnSe) polycrystalline material. The first random phase matched OPO was demonstrated with more than one octave spectrum (3.1– 9μm), which is also the first OPO based on ZnSe.
Advisors/Committee Members: Vodopyanov, Konstantin.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Ru, Q. (2019). Broadband Mid-infrared Frequency Combs Generated via Frequency Division. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6570
Chicago Manual of Style (16th Edition):
Ru, Qitian. “Broadband Mid-infrared Frequency Combs Generated via Frequency Division.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6570.
MLA Handbook (7th Edition):
Ru, Qitian. “Broadband Mid-infrared Frequency Combs Generated via Frequency Division.” 2019. Web. 22 Feb 2020.
Vancouver:
Ru Q. Broadband Mid-infrared Frequency Combs Generated via Frequency Division. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6570.
Council of Science Editors:
Ru Q. Broadband Mid-infrared Frequency Combs Generated via Frequency Division. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6570
University of Central Florida
20.
Talukder, Md Javed Rouf.
High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6583
► See-through augmented reality and virtual reality displays are emerging due to their widespread applications in education, engineering design, medical, retail, transportation, automotive, aerospace, gaming, and…
(more)
▼ See-through augmented reality and virtual reality displays are emerging due to their widespread applications in education, engineering design, medical, retail, transportation, automotive, aerospace, gaming, and entertainment. For augmented reality and virtual reality displays, high-resolution density, high luminance, fast response time and high ambient contrast ratio are critically needed. High-resolution density helps eliminate the screen-door effect, high luminance and fast response time enable low duty ratio operation, which plays a key role for suppressing image blurs. A dimmer placed in front of AR display helps to control the incident background light, which in turn improves the image contrast. In this dissertation, we have focused three crucial display metrics: high luminance, fast motion picture response time (MPRT) and high ambient contrast ratio.
We report a fringe-field switching liquid crystal display, abbreviated as d-FFS LCD, by using a low viscosity material and new diamond-shape electrode configuration. Our proposed device shows high transmittance, fast motion picture response time, low operation voltage, wide viewing angle, and indistinguishable color shift and gamma shift. We also investigate the rubbing angle effects on transmittance and response time. When rubbing angle is 0 degree, the virtual wall effect is strong, resulting in fast response time but compromised transmittance. When rubbing angle is greater than 1.2 degree, the virtual walls disappear, as a result, the transmittance increases dramatically, but the tradeoff is in slower response time. We also demonstrate a photo-responsive guest-host liquid crystal (LC) dimmer to enhance the ambient contrast ratio in augmented reality displays. The LC composition consists of photo-stable chiral agent, photosensitive azobenzene, and dichroic dye in a nematic host with negative dielectric anisotropy. In this device, transmittance changes from bright state to dark state by exposing a low intensity UV or blue light. Reversal process can be carried out by red light or thermal effect. Such a polarizer-free photo-activated dimmer can also be used for wide range of applications, such as diffractive photonic devices, portable information system, vehicular head-up displays, and smart window for energy saving purpose. A dual-stimuli polarizer-free dye-doped liquid crystal (LC) device is demonstrated as a dimmer. Upon UV/blue light exposure, the LC directors and dye molecules turn from initially vertical alignment (high transmittance state) to twisted fingerprint structure (low transmittance state). The reversal process is accelerated by combining a longitudinal electric field to unwind the LC directors from twisted fingerprint to homeotropic state, and a red light to transform the cis azobenzene back to trans. Such an electric-field-assisted reversal time can be reduced from ~10s to a few milliseconds, depending on the applied voltage. Considering power consumption, low manufacturing cost, and large fabrication tolerance, this device can be used as a smart…
Advisors/Committee Members: Wu, Shintson.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Talukder, M. J. R. (2019). High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6583
Chicago Manual of Style (16th Edition):
Talukder, Md Javed Rouf. “High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6583.
MLA Handbook (7th Edition):
Talukder, Md Javed Rouf. “High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality.” 2019. Web. 22 Feb 2020.
Vancouver:
Talukder MJR. High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6583.
Council of Science Editors:
Talukder MJR. High Performance Liquid Crystal Devices for Augmented Reality and Virtual Reality. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6583
University of Central Florida
21.
Hayenga, William.
Fundamental Properties of Metallic Nanolasers.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6604
► The last two decades have witnessed tremendous advancements in the area of nanophotonics and plasmonics, which has helped propel the development of integrated photonic sources.…
(more)
▼ The last two decades have witnessed tremendous advancements in the area of nanophotonics and plasmonics, which has helped propel the development of integrated photonic sources. Of central importance to such circuits is compact, scalable, low threshold, and efficient coherent sources that can be driven at high modulation frequencies. In this regard, metallic nanolasers offer a unique platform. Their introduction has enabled confinement of light at a subwavelength scale and the ultra-small size of the modes afforded by these structures allows for cavity enhancing effects that can help facilitate thresholdless lasing and large direct modulation bandwidths. In this report, I present my work on the study of the fundamental properties of metallic nanolasers. I start with a rate equation model to predict threshold behavior and the modulation response of metallic nanolasers. Next, I explain the second-order coherence measurement setup that was built, based on a modified Hanbury-Brown and Twiss experiment, to assess the intensity autocorrelation of various optically pumped metallic nanolasers. These studies concluded that metallic coaxial and disk-shaped nanolasers are capable of generating truly coherent radiation. Subsequently, design considerations are taken into account for electrically pumped coaxial nanolasers. This has led to the demonstration of electrically injected coaxial and disk-shaped nanolasers at cryogenic temperatures. Lastly, the appearance of collective behaviors in metallic nanolasers lattices is explored. Individually supporting modes that are highly vectorial by nature, when such cavities are fabricated in close proximity to one another, coupling through their overlapping fields results in the formation of a set of supermodes. The tendency of the system to minimize the overall loss leads to each element of the lattice having a geometric dependent field distribution and helps promotes single-mode lasing. We show both through simulations and experimentally that this effect can lead to the direct generation of vector vortices.
Advisors/Committee Members: Khajavikhan, Mercedeh.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Hayenga, W. (2019). Fundamental Properties of Metallic Nanolasers. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6604
Chicago Manual of Style (16th Edition):
Hayenga, William. “Fundamental Properties of Metallic Nanolasers.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6604.
MLA Handbook (7th Edition):
Hayenga, William. “Fundamental Properties of Metallic Nanolasers.” 2019. Web. 22 Feb 2020.
Vancouver:
Hayenga W. Fundamental Properties of Metallic Nanolasers. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6604.
Council of Science Editors:
Hayenga W. Fundamental Properties of Metallic Nanolasers. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6604
University of Central Florida
22.
Suttinger, Matthew.
Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance.
Degree: 2017, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6088
► Quantum Cascade Lasers are a novel source of coherent infrared light, unique in their tunability over the mid-infrared and terahertz range of frequencies. Advances in…
(more)
▼ Quantum Cascade Lasers are a novel source of coherent infrared light, unique in their tunability over the mid-infrared and terahertz range of frequencies. Advances in bandgap engineering and semiconductor processing techniques in recent years have led to the development of highly efficient quantum cascade lasers capable of room temperature operation. Recent work has demonstrated power scaling with broad area quantum cascade lasers by increasing active region width beyond the standard ~10 ?m. Taking into account thermal effects caused by driving a device with electrical power, an experimentally fitted model is developed to predict the optical power output in both pulsed and continuous operation with varying device geometry and minor changes to quantum cascade laser active region design. The effects of the characteristic temperatures of threshold current density and slope efficiency, active region geometry, and doping, on output power are studied in the model. The model is then used to refine the active region design for increased power out in continuous operation for a broad area design. Upon testing the new design, new thermal effects on rollover current density are observed. The model is then refined to reflect the new findings and more accurately predict output power characteristics.
Advisors/Committee Members: Lyakh, Arkadiy.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Suttinger, M. (2017). Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance. (Masters Thesis). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6088
Chicago Manual of Style (16th Edition):
Suttinger, Matthew. “Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance.” 2017. Masters Thesis, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6088.
MLA Handbook (7th Edition):
Suttinger, Matthew. “Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance.” 2017. Web. 22 Feb 2020.
Vancouver:
Suttinger M. Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance. [Internet] [Masters thesis]. University of Central Florida; 2017. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6088.
Council of Science Editors:
Suttinger M. Thermal and Waveguide Optimization of Broad Area Quantum Cascade Laser Performance. [Masters Thesis]. University of Central Florida; 2017. Available from: https://stars.library.ucf.edu/etd/6088
University of Central Florida
23.
Vazquez-Guardado, Abraham.
Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions.
Degree: 2018, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6262
► Light-matter interaction is a pivotal effect that involves the synergetic interplay of electromag- netic fields with fundamental particles. In this regard localized surface plasmons (LSP)…
(more)
▼ Light-matter interaction is a pivotal effect that involves the synergetic interplay of electromag- netic fields with fundamental particles. In this regard localized surface plasmons (LSP) arise from coherent interaction of the electromagnetic field with the collective oscillation of free electrons in confined sub-wavelength environments. Their most attractive properties are strong field en- hancements at the near field, highly inhomogeneous, peculiar temporal and spatial distributions and unique polarization properties. LSP systems also offer a unique playground for fundamental electromagnetic physics where micro-scale systemic properties can be studied in the macro-scale. These important properties and opportunities are brought up in this work where I study hybrid cavity-coupled plasmonic systems in which the weak plasmonic element is far-field coupled with the photonic cavity by properly tuning its phase. In this work I preset the fundamental understand- ing of such a complex systems from the multi-resonance interaction picture along experimental demonstration. Using this platform and its intricate near fields I further demonstrate a novel mech- anism to generate superchiral light: a field polarization property that adds a degree of freedom to light-matter interactions at the nanoscale exploited in advanced sensing applications and surface effect processes. Finally, the detection of non-chiral analytes, such as proteins, neurotransmit- ters or nanoparticles, and more complex chiral analytes, such as proteins and its conformation states, amino acids or chiral molecules at low concentrations is demonstrated in several biosensing applications. The accompanied experiential demonstrations were accomplished using the nanoim- printing technique, which places the cavity-coupled hybrid plasmonic system as a unique platform towards realistic applications not limited by expensive lithographic techniques.
Advisors/Committee Members: Chanda, Debashis.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Vazquez-Guardado, A. (2018). Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6262
Chicago Manual of Style (16th Edition):
Vazquez-Guardado, Abraham. “Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions.” 2018. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6262.
MLA Handbook (7th Edition):
Vazquez-Guardado, Abraham. “Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions.” 2018. Web. 22 Feb 2020.
Vancouver:
Vazquez-Guardado A. Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions. [Internet] [Doctoral dissertation]. University of Central Florida; 2018. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6262.
Council of Science Editors:
Vazquez-Guardado A. Cavity-Coupled Plasmonic Systems for Enhanced Light-Matter Interactions. [Doctoral Dissertation]. University of Central Florida; 2018. Available from: https://stars.library.ucf.edu/etd/6262
University of Central Florida
24.
Yang, Xu.
Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers.
Degree: 2016, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5205
► Nowadays, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are the most popular optical sources in short-reach data communications. In the commercial oxide VCSEL technology, an oxide aperture is…
(more)
▼ Nowadays, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are the most popular optical sources in short-reach data communications. In the commercial oxide VCSEL technology, an oxide aperture is created inside resonant cavity in realizing good mode and current confinement, however, high electrical resistance comes along with forming the oxide aperture and the electrical parasitic bandwidth becomes the main limitation in modulation speed.
In this report, electrical bandwidths of oxide-free lithographic VCSELs have been studied along with their general lasing properties. Due to the new ways of fabricating the aperture, record low resistances have been achieved in oxide-free lithographic VCSELs with various sizes, while high slope efficiencies and high output powers have been maintained. High speed simulation has been performed showing the very low differential resistances will benefit much to the electrical parasitic bandwidths, and are expected to produce higher modulation speed. A bottom emitting structure has been proposed and analyzed, showing reduction in both mirror resistance and capacitance will further improve the modulation speed. The total 3-dB modulation bandwidth is expected to be 50-80 GHz, much higher than the bandwidth reached in existing oxide VCSELs.
Lithographic VCSELs also show superior lasing characteristics, including record low thermal resistance and record high output power. The maximum power exceeds 19 mW in a 6 µm device and over 50 % power conversion efficiency has been achieved. A maximum single mode operation power of 5 mW has been observed from a 1 µm diameter VCSEL. High temperature stress testing has been performed showing lithographic VCSELs can operate more reliably than oxide VCSELs under extreme operating conditions. Lithographic VCSEL with low electrical resistance, single-mode operation, high efficiency, and high power will be a strong candidate as the optical source in high speed data communications, as well as other applications such as high power VCSEL arrays and optical sensing.
Advisors/Committee Members: Deppe, Dennis.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Yang, X. (2016). Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5205
Chicago Manual of Style (16th Edition):
Yang, Xu. “Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers.” 2016. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5205.
MLA Handbook (7th Edition):
Yang, Xu. “Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers.” 2016. Web. 22 Feb 2020.
Vancouver:
Yang X. Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers. [Internet] [Doctoral dissertation]. University of Central Florida; 2016. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5205.
Council of Science Editors:
Yang X. Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers. [Doctoral Dissertation]. University of Central Florida; 2016. Available from: https://stars.library.ucf.edu/etd/5205
University of Central Florida
25.
Li, Mingxin.
Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers.
Degree: 2016, University of Central Florida
URL: https://stars.library.ucf.edu/etd/5204
► Vertical-cavity surface-emitting lasers (VCSELs) have been greatly improved and successfully commercialized over the past few decades owing to their ability to provide both mode and…
(more)
▼ Vertical-cavity surface-emitting lasers (VCSELs) have been greatly improved and successfully commercialized over the past few decades owing to their ability to provide both mode and current confinement that enables low energy consumption, high efficiency and high modulation speed. However, further improvement of oxide VCSELs is limited by the nature of the oxide aperture because of self-heating, internal strain and difficulties in precise size control.
In this dissertation, VCSELs using lithographic approach are demonstrated to overcome the limitations of oxide VCSELs, in which an intra-cavity phase shifting mesa is applied to define the device size and provide optical mode and electrical current confinement instead of an oxide aperture. A newly developed model of intrinsic modulation response is proposed and analyzed to focus on the thermal limit of the modulation speed of VCSELs. The results show that both the temperature dependent differential gain and stimulated emission rate impact laser speed and the stimulated emission rate dominates the speed limit. Thermal limits of modulation response are compared for oxide and lithographic VCSELs for various sizes. The results predict that the intrinsic modulation response can be significantly increased by using lithographic VCSELs due to low thermal resistance and reduced mode volume while maintaining high efficiency. The intrinsic bandwidth could exceed 100 GHz for a 2-?m-diameter lithographic VCSEL. Combined with low electrical parasitics, it is expected to produce over 100 Gb/s data rate from a single directly modulated laser. VCSELs designed for high speed are discussed and their characteristics are demonstrated.
Advisors/Committee Members: Deppe, Dennis.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Li, M. (2016). Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/5204
Chicago Manual of Style (16th Edition):
Li, Mingxin. “Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers.” 2016. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/5204.
MLA Handbook (7th Edition):
Li, Mingxin. “Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers.” 2016. Web. 22 Feb 2020.
Vancouver:
Li M. Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers. [Internet] [Doctoral dissertation]. University of Central Florida; 2016. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/5204.
Council of Science Editors:
Li M. Intrinsic Modulation Response Modeling and Analysis for Lithographic Vertical-Cavity Surface-Emitting Lasers. [Doctoral Dissertation]. University of Central Florida; 2016. Available from: https://stars.library.ucf.edu/etd/5204
University of Central Florida
26.
Liu, Huiyuan.
Mode Coupling in Space-division Multiplexed Systems.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6754
► Even though fiber-optic communication systems have been engineered to nearly approach the Shannon capacity limit, they still cannot meet the exponentially-growing bandwidth demand of the…
(more)
▼ Even though fiber-optic communication systems have been engineered to nearly approach the Shannon capacity limit, they still cannot meet the exponentially-growing bandwidth demand of the Internet. Space-division multiplexing (SDM) has attracted considerable attention in recent years due to its potential to address this capacity crunch. In SDM, the transmission channels support more than one spatial mode, each of which can provide the same capacity as a single-mode fiber. To make SDM practical, crosstalk among modes must be effectively managed. This dissertation presents three techniques for crosstalk management for SDM. In some cases such as intra-datacenter interconnects, even though mode crosstalk cannot be completely avoided, crosstalk among mode groups can be suppressed in properly-designed few-mode fibers to support mode group-multiplexed transmission. However, in most cases, mode coupling is unavoidable. In free-space optical (FSO) communication, mode coupling due to turbulence manifests as wavefront distortions. Since there is almost no modal dispersion in FSO, we demonstrate the use of few-mode pre-amplified receivers to mitigate the effect of turbulence without using adaptive optics. In fiber-optic communication, multi-mode fibers or long-haul few-mode fibers not only suffer from mode crosstalk but also large modal dispersion, which can only be compensated electronically using multiple-input-multiple-output (MIMO) digital signal processing (DSP). In this case, we take the counterintuitive approach of introducing strong mode coupling to reduce modal group delay and DSP complexity.
Advisors/Committee Members: Li, Guifang.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Liu, H. (2019). Mode Coupling in Space-division Multiplexed Systems. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6754
Chicago Manual of Style (16th Edition):
Liu, Huiyuan. “Mode Coupling in Space-division Multiplexed Systems.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6754.
MLA Handbook (7th Edition):
Liu, Huiyuan. “Mode Coupling in Space-division Multiplexed Systems.” 2019. Web. 22 Feb 2020.
Vancouver:
Liu H. Mode Coupling in Space-division Multiplexed Systems. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6754.
Council of Science Editors:
Liu H. Mode Coupling in Space-division Multiplexed Systems. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6754
University of Central Florida
27.
Mcgill, Daniel.
Processing of Advanced Infrared Materials.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6693
► Infrared transparent glassy and crystalline materials often have unique and complex processing requirements but are an important class of materials for such applications as optical…
(more)
▼ Infrared transparent glassy and crystalline materials often have unique and complex processing requirements but are an important class of materials for such applications as optical windows, lenses, waveplates, polarizers and beam splitters. This thesis investigates two specific materials, one amorphous and one crystalline, that are candidates for use in the short and midwave-infrared and mid and longwave infrared, respectively. It is demonstrated that an innovative uniaxial sintering process, which uses a sacrificial pressure-transmitting medium, can be used to fully densify a 70TeO2-20WO3-10La2O3 (TWL) glass powder. The characteristics of the sintered TWL glass is compared to that of a parent glass produced through a conventional melt/quench process to ascertain the impact of process-specific property changes on the resulting material. Additionally, the design, construction and characterization of a custom-made transparent Bridgman crystal growth furnace is undertaken to enable growth of highly birefringent tellurium single crystal. The key obstacles that need to be overcome to scale up the size of the grown crystals are summarized with the end goal of producing commercial grade optical elements.
Advisors/Committee Members: Richardson, Kathleen.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Mcgill, D. (2019). Processing of Advanced Infrared Materials. (Masters Thesis). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6693
Chicago Manual of Style (16th Edition):
Mcgill, Daniel. “Processing of Advanced Infrared Materials.” 2019. Masters Thesis, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6693.
MLA Handbook (7th Edition):
Mcgill, Daniel. “Processing of Advanced Infrared Materials.” 2019. Web. 22 Feb 2020.
Vancouver:
Mcgill D. Processing of Advanced Infrared Materials. [Internet] [Masters thesis]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6693.
Council of Science Editors:
Mcgill D. Processing of Advanced Infrared Materials. [Masters Thesis]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6693
University of Central Florida
28.
Nye, Nicholas.
Non-Hermitian and Space-Time Mode Management.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6694
► In the last few years, optics has witnessed the emergence of two fields namely metasurfaces and parity-time (PT) symmetry. Optical metasurfaces are engineered structures that…
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▼ In the last few years, optics has witnessed the emergence of two fields namely metasurfaces and parity-time (PT) symmetry. Optical metasurfaces are engineered structures that provide unique responses to electromagnetic waves, absent in natural materials. On the other hand, PT symmetry has emerged from quantum mechanics, when a new class of non-Hermitian Hamiltonian quantum systems was shown to have real eigenvalues. In this work, we demonstrate how PT-symmetric diffractive structures are capable of eliminating diffraction orders in specific directions, while maintaining/enhancing the remaining orders. In the second part of this work, we emphasize on supersymmetry (SUSY) and its applications in optics. Even though the full ramification of SUSY in high-energy physics is still a matter of debate that awaits experimental validation, supersymmetric techniques have already found their way into low-energy physics. In this work, we apply certain isospectral techniques in order to achieve single mode lasing in multi-element waveguide systems, where multimode chaotic emission is expected. In the third part of this dissertation, we emphasize on dynamically reconfigurable nanoparticle platforms. By exploiting the dielectrophoresis effect, we demonstrate how controllable lasing can be achieved in random photonic arrangements. Although this work focuses on the case of controlling random lasers, we expect that the proposed nanoparticle architecture can incorporate heterogeneous materials of a wide range of optical functionalities, including gain, scattering, plasmonic resonance, and nonlinearity. In the last part of the dissertation, we demonstrate the capability of synthesizing space-time (ST) wave packets, based on new propagation-invariant elementary solutions of the wave equation identified through a complexification of the spatial and temporal degrees of freedom. By establishing the connection between ST propagation-invariant pulses and tilted-pulse-front pulses, a path is opened to exploiting the unique attributes of such wave packets both in nonlinear and quantum optics.
Advisors/Committee Members: Christodoulides, Demetrios.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA (6th Edition):
Nye, N. (2019). Non-Hermitian and Space-Time Mode Management. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6694
Chicago Manual of Style (16th Edition):
Nye, Nicholas. “Non-Hermitian and Space-Time Mode Management.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6694.
MLA Handbook (7th Edition):
Nye, Nicholas. “Non-Hermitian and Space-Time Mode Management.” 2019. Web. 22 Feb 2020.
Vancouver:
Nye N. Non-Hermitian and Space-Time Mode Management. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6694.
Council of Science Editors:
Nye N. Non-Hermitian and Space-Time Mode Management. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6694
University of Central Florida
29.
Sun, Yangyang.
Computational Imaging Systems for High-speed, Adaptive Sensing Applications.
Degree: 2019, University of Central Florida
URL: https://stars.library.ucf.edu/etd/6755
► Driven by the advances in signal processing and ubiquitous availability of high-speed low-cost computing resources over the past decade, computational imaging has seen the growing…
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▼ Driven by the advances in signal processing and ubiquitous availability of high-speed low-cost computing resources over the past decade, computational imaging has seen the growing interest. Improvements on spatial, temporal, and spectral resolutions have been made with novel designs of imaging systems and optimization methods. However, there are two limitations in computational imaging. 1), Computational imaging requires full knowledge and representation of the imaging system called the forward model to reconstruct the object of interest. This limits the applications in the systems with a parameterized unknown forward model such as range imaging systems. 2), the regularization in the optimization process incorporates strong assumptions which may not accurately reflect the a priori distribution of the object. To overcome these limitations, we propose 1) novel optimization frameworks for applying computational imaging on active and passive range imaging systems and achieve 5-10 folds improvement on temporal resolution in various range imaging systems; 2) a data-driven method for estimating the distribution of high dimensional objects and a framework of adaptive sensing for maximum information gain. The adaptive strategy with our proposed method outperforms Gaussian process-based method consistently. The work would potentially benefit high-speed 3D imaging applications such as autonomous driving and adaptive sensing applications such as low-dose adaptive computed tomography(CT).
Advisors/Committee Members: Pang, Sean.
Subjects/Keywords: Electromagnetics and Photonics; Optics
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APA ·
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MLA ·
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CSE |
Export
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APA (6th Edition):
Sun, Y. (2019). Computational Imaging Systems for High-speed, Adaptive Sensing Applications. (Doctoral Dissertation). University of Central Florida. Retrieved from https://stars.library.ucf.edu/etd/6755
Chicago Manual of Style (16th Edition):
Sun, Yangyang. “Computational Imaging Systems for High-speed, Adaptive Sensing Applications.” 2019. Doctoral Dissertation, University of Central Florida. Accessed February 22, 2020.
https://stars.library.ucf.edu/etd/6755.
MLA Handbook (7th Edition):
Sun, Yangyang. “Computational Imaging Systems for High-speed, Adaptive Sensing Applications.” 2019. Web. 22 Feb 2020.
Vancouver:
Sun Y. Computational Imaging Systems for High-speed, Adaptive Sensing Applications. [Internet] [Doctoral dissertation]. University of Central Florida; 2019. [cited 2020 Feb 22].
Available from: https://stars.library.ucf.edu/etd/6755.
Council of Science Editors:
Sun Y. Computational Imaging Systems for High-speed, Adaptive Sensing Applications. [Doctoral Dissertation]. University of Central Florida; 2019. Available from: https://stars.library.ucf.edu/etd/6755
McMaster University
30.
Malekiha, Mahdi.
ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS.
Degree: MASc, 2011, McMaster University
URL: http://hdl.handle.net/11375/11037
► The rapid development of fiber optic communication systems requires higher transmission data rate and longer reach. This thesis deals with the limiting factors in…
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▼ The rapid development of fiber optic communication systems requires higher transmission data rate and longer reach. This thesis deals with the limiting factors in design of long-haul fiber optic communication systems and the techniques used to suppress their resulting impairments. These impairments include fiber chromatic dispersion, the Ker nonlinearity and nonlinear phase noise due to amplified spontaneous emission. In the first part of this thesis, we investigate the effect of amplified spontaneous noise in quasi-linear systems. In quasi-linear systems, inline optical amplifiers change the amplitude of the optical field envelope randomly and fiber nonlinear effects such as self phase modulation (SPM) convert the amplitude fluctuations to phase fluctuations which is known as nonlinear phase noise. For M-ary phase shift keying (PSK) signals, symbol error probability is determined solely by the probability density function (PDF) of the phase. Under the Gaussian PDF assumption, the phase variance can be related to the symbol error probability for PSK signals. We implemented the simulation based on analytical phase noise variance and Monte-Carlo simulation, and it is found that the analytical approximation is in good agreement with numerical simulations. We have developed analytical expressions for the linear and nonlinear phase noise variance due to SPM using second-order perturbation theory. It is found that as the transmission reach and/or lunch power increase, the variance of the phase noise calculated using first order perturbation theory becomes inaccurate. However, the variance calculated using second order perturbation theory is in good agreement with numerical simulations. We have also showed that the analytical formula given in this chapter for the variance of nonlinear phase noise can be used as a design tool to investigate the optimum system design parameters such as average power and dispersion maps for coherent fiber optic systems based on phase shift keying due to the fact that the numerical simulation of nonlinear Schrodinger (NLS) equation is time consuming, however, the analytical method based on solving NLS equation using perturbation approximation is quite efficient and therefore the analytical variance can be obtained more easily without requiring extensive computational efforts, and also with fairly good accuracy. In the second part of this thesis, an improved optical signal processing using highly nonlinear fibers is studied. This technique, optical backward propagation (OBP), can compensate for the fiber dispersion and nonlinearity using optical nonlinearity compensators (NLC) and dispersion compensating fibers (DCF), respectively. In contrast, digital backward propagation (DBP) uses the high-speed digital signal processing (DSP) unit to compensate for the fiber nonlinearity and dispersion digital domain. NLC imparts a phase shift that is equal in magnitude to the nonlinear phase shift due to Fiber propagation, but opposite in sign. In principle, BP schemes could undo the…
Advisors/Committee Members: Kumar, Shiva, Electrical and Computer Engineering.
Subjects/Keywords: Fiber-Optic; Communication Systems; Electromagnetics and photonics; Electromagnetics and photonics
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Malekiha, M. (2011). ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/11037
Chicago Manual of Style (16th Edition):
Malekiha, Mahdi. “ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS.” 2011. Masters Thesis, McMaster University. Accessed February 22, 2020.
http://hdl.handle.net/11375/11037.
MLA Handbook (7th Edition):
Malekiha, Mahdi. “ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS.” 2011. Web. 22 Feb 2020.
Vancouver:
Malekiha M. ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS. [Internet] [Masters thesis]. McMaster University; 2011. [cited 2020 Feb 22].
Available from: http://hdl.handle.net/11375/11037.
Council of Science Editors:
Malekiha M. ANALYSIS OF NONLINEAR EFFECTS AND THEIR MITIGATION IN FIBER-OPTIC COMMUNICATION SYSTEMS. [Masters Thesis]. McMaster University; 2011. Available from: http://hdl.handle.net/11375/11037
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Open Access Theses and Dissertations