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You searched for +publisher:"McMaster University" +contributor:("Cassidy, Daniel T."). Showing records 1 – 2 of 2 total matches.

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McMaster University

1. Khan, Ferdous Karim. Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers.

Degree: PhD, 2010, McMaster University

A detailed analysis of coupled cavity semiconductor lasers with asymmetric multiple quantum well (AMQW) active regions is presented in this thesis. The analysis involved design, fabrication, characterization, and simulation of these devices. Although the coupled cavity devices can be multi sectioned, the devices discussed in this thesis are two sectioned. A below threshold model for an AMQW coupled cavity device is developed. Non-linear fits of the below threshold spectral data to that obtained from the model were used to extract optimized device parameters. These fits helped to create an understanding of the operation of the devices and paved the way for improved device performance. Optimized device parameters obtained from the below threshold model were later used as input parameters in the development of an above threshold model. This model verified the wavelength selection mechanism employed by coupled cavity diode lasers and predicted the longitudinal modes for sets of injection currents. Optical coherence tomography (OCT) is an application where much interest has recently been drawn. The coupled cavity devices fabricated in this work applied with proper modulation of the injection currents and followed by subsequent time averaging have demonstrated short coherence length (-15 μm) and can be an excellent source for synthesized OCT. Rapid wavelength switching (-70 ns, the measurement was limited by detector response time) over the whole range has also been experimentally shown. Because of the high speed (relative to mechanical) wavelength switching ability, AMQW coupled cavity devices have the potential for applications requiring real time measurements including real time synthesized OCT.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Cassidy, Daniel T., Engineering Physics.

Subjects/Keywords: coupled cavity semiconductor laser; asymmetric multiple quantum well; optical coherence technology; wavelength switching

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Khan, F. K. (2010). Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/19078

Chicago Manual of Style (16th Edition):

Khan, Ferdous Karim. “Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers.” 2010. Doctoral Dissertation, McMaster University. Accessed April 14, 2021. http://hdl.handle.net/11375/19078.

MLA Handbook (7th Edition):

Khan, Ferdous Karim. “Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers.” 2010. Web. 14 Apr 2021.

Vancouver:

Khan FK. Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers. [Internet] [Doctoral dissertation]. McMaster University; 2010. [cited 2021 Apr 14]. Available from: http://hdl.handle.net/11375/19078.

Council of Science Editors:

Khan FK. Design, Fabrication and Analysis of Broadly Tunable Asymmetric Multiple Quantum Well Coupled Cavity Diode Lasers. [Doctoral Dissertation]. McMaster University; 2010. Available from: http://hdl.handle.net/11375/19078


McMaster University

2. Enshasy, Hesham. Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers.

Degree: PhD, 2010, McMaster University

Title: Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers, Author: Hesham Enshasy, Location: Mills

Broadly tunable InGaAsP/InP asymmetric multiple quantum well (AMQW) ridge waveguide laser diodes suffer from low output power. The output power problem of the AMQW laser diodes limits the use of these lasers in certain applications. Both theoretical and experimental studies were carried out in this work to understand the reasons behind this output power problem and to put forth solutions to this problem. As a starting point a commercial beam propagation method (BPM) optical simulator was used to optimize the confinement factor of the laser diodes. The laser diode output power almost doubled as a result of optical confinement optimization, which opens the door for improvement from electrical and thermal optimization. A commercially available partial differential equation solver, FlexPDE, was used to solve the main electronic and thermal equations and simulate a laser diode device. The FlexPDE simulations -which were validated with published data-showed poor current injection efficiency to the center of the device active region. The FlexPDE simulations showed that the main reason for this poor current injection efficiency is the ridge structure. Since the ridge structure is an essential part of this type of laser diode, effort was put forth to reduce the effect of the ridge structure on the current injection efficiency. Both simulation and experimental data showed that extending the doping profile closer to the active area would improve significantly the output power. On the other hand, a proposed forced electrical confinement method showed potential to improve the output power of the device theoretically and experimentally. The over all output power improvement went from a range of 2-5 m W to a range of 15-18 m W as a result of this study. A discussion of the two distinct output power profiles is included in the study, while detailed explanations of the dip in the power profile supported by experimental data are reported. A new method of distance measurement using one of the first, optimized, broadly tunable InGaAsP/InP short-external-cavity diode lasers is reported. Non-linear, least squares fitting method was used to extract estimates of distance from the raw data. This fitting method together with the wide tuning range (100 nm) made it possible to achieve sub-micron resolution of distance even in the presence of noise.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Cassidy, Daniel T., Engineering Physics.

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Enshasy, H. (2010). Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/19480

Chicago Manual of Style (16th Edition):

Enshasy, Hesham. “Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers.” 2010. Doctoral Dissertation, McMaster University. Accessed April 14, 2021. http://hdl.handle.net/11375/19480.

MLA Handbook (7th Edition):

Enshasy, Hesham. “Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers.” 2010. Web. 14 Apr 2021.

Vancouver:

Enshasy H. Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers. [Internet] [Doctoral dissertation]. McMaster University; 2010. [cited 2021 Apr 14]. Available from: http://hdl.handle.net/11375/19480.

Council of Science Editors:

Enshasy H. Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers. [Doctoral Dissertation]. McMaster University; 2010. Available from: http://hdl.handle.net/11375/19480

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