by Chan Lai Yin Simon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references. / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Background --- p.1-2 / Chapter 1.2 --- Properties of the InGaAsP quaternary alloy on InP substrate --- p.2 / Chapter 1.2.1 --- Physical Properties of In1-xGaxASyP1-y on InP substrate --- p.3-4 / Chapter 1.2.2 --- Optical Properties of In1-xGaxASyP1-y on InP substrate --- p.4-7 / Chapter 1.2.3 --- Nonlinear Optical Property of InGaAsP --- p.7-9 / Chapter 1.3 --- Fabrication of InGaAsP/InP rib waveguide / Chapter 1.3.1 --- Epitaxial Growth of In1-xGaxASyP1-y on InP substrate by MOCVD --- p.9 / Chapter 1.3.2 --- Etching of the five layer In1-xGaxASyP1-y slab waveguide --- p.9-12 / Chapter 1.4 --- Overview of the thesis --- p.12-13 / References --- p.13-15 / Chapter Chapter 2: --- Modal analysis of the single mode III-V semiconductor waveguidesin multi-layer rib structure by Effective Index Method / Chapter 2.1 --- Introduction --- p.16-17 / Chapter 2.2 --- Modal analysis of the rib waveguides --- p.17-27 / Chapter 2.3 --- Optical Confinement in rib waveguide --- p.28-30 / Chapter 2.4 --- Conclusions and discussions --- p.30-31 / References --- p.31-33 / Chapter Chapter 3: --- Ultrashort Pulsewidth Measurement Part I / Chapter 3.1 --- Introduction --- p.34 / Chapter 3.2 --- Pulsewidth measurement by streak camera --- p.34-37 / Chapter 3.3 --- Pulsewidth measurement by nonlinear autocorrelation --- p.37-40 / Chapter 3.3.1 --- Second Harmonic Generation Autocorrelator --- p.40-43 / Chapter 3.3.2 --- Two Photon Fluorescence Autocorrelator --- p.43-44 / Chapter 3.4 --- Two Photon Absorption Waveguide Autocorrelator --- p.45 / Chapter 3.4.1 --- TPA theory --- p.45-48 / Chapter 3.4.2 --- Autocorrelation Measurement by TPA in InGaAsP Waveguide --- p.48-51 / Chapter 3.4.3 --- The Estimated performance of the TPA Waveguide Autocorrelator --- p.52 / References --- p.52-57 / Chapter Chapter 4: --- Ultrashort Pulsewidth Measurement Part II: High Sensitivity Two Photon Absorption InGaAsP Waveguide Autocorrelator for Low Power Pulsewidth Measurement of 1.55μm Waveguide Pulses / Chapter 4.1 --- Introduction --- p.58-60 / Chapter 4.2 --- Waveguide structures --- p.60 / Chapter 4.3 --- Practical Implementation of the TPA Waveguide Autocorrelator / Chapter 4.3.1 --- Mirror arrangement for the delay system --- p.61 -63 / Chapter 4.3.2 --- Alignment and Coupling of the InGaAsP/InP Waveguide --- p.63-64 / Chapter 4.3.3 --- TPA photocurrent detection --- p.64-65 / Chapter 4.4 --- Experimental results --- p.65-67 / Chapter 4.4.1 --- Pulsewidth measurement of the TPA InGaAsP waveguide autocorrelator --- p.67-71 / Chapter 4.4.2 --- Spectral analysis by the TPA InGaAsP waveguide autocorrelator --- p.71 -73 / Chapter 4.5 --- Conclusions and discussions --- p.73-75 / References --- p.75-78 / Chapter Chapter 5: --- Picosecond Pulses Generation by Colliding-Pulse Mode-locking of a Fabry-Perot Laser Diode with an Intra-cavity Gradual Degradation Defect / Chapter 5.1 --- Introduction --- p.79-80 / Chapter 5.2 --- Gain-switching --- p.80-84 / Chapter 5.3 --- Colliding Pulse Mode-locking --- p.84-85 / Chapter 5.3.1 --- Degradation of diode laser --- p.85-86 / Chapter 5.3.2 --- CPM Theory --- p.86-89 / Chapter 5.3.3 --- Experimental results --- p.89-92 / Chapter 5.4 --- Conclusions and discussions --- p.92-93 / References --- p.94-98 / Chapter Chapter 6: --- Conclusions / Chapter 6.1 --- Summary of the Research / Chapter 6.1.1 --- Theoretical Results --- p.99-100 / Chapter 6.1.2 --- Experimental Results --- p.101-104 / Chapter 6.2 --- Future Development / Chapter 6.2.1 --- Improvement of the TPA InGaAsP waveguide autocorrelator --- p.105 / Chapter 6.2.2 --- Future development of III-V semiconductor waveguides --- p.105-107 / References --- p.107-108 / Appendix --- p.109-121

Chen, Kejian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 156-164). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

by So King Lung, Benny. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 102-109). / ABSTRACT --- p.v / ACKNOWLEDGEMENTS --- p.vii / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.xiii / Chapter Chapter 1 --- Background of the study --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Surface passivation techniques --- p.3 / Chapter 1.2.1 --- Sulfide solution passivation --- p.3 / Chapter 1.2.2 --- Gas-phase sulfide passivation --- p.4 / Chapter 1.3 --- Surface structure of sulfide-passivated surface --- p.5 / Chapter 1.4 --- Objectives of the present study --- p.7 / Chapter Chapter 2 --- Instrumentation --- p.9 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- X-ray photoelectron spectroscopy (XPS) --- p.9 / Chapter 2.2.1 --- The development of XPS --- p.9 / Chapter 2.2.2 --- Basic principle of XPS --- p.9 / Chapter 2.2.3 --- Quantitative analysis of XPS --- p.14 / Chapter 2.2.3.1 --- Atomic concentration of a homogenous material --- p.14 / Chapter 2.2.3.2 --- Layer structure --- p.15 / Chapter 2.2.3.3 --- Simulation of XPS atomic concentration ratios from proposed surface structural models --- p.17 / Chapter 2.2.4 --- XPS experiment --- p.19 / Chapter 2.3 --- Low energy electron diffraction (LEED) --- p.21 / Chapter 2.3.1 --- The development of LEED --- p.21 / Chapter 2.3.2 --- Basic principle of LEED --- p.23 / Chapter 2.3.3 --- LEED experiment --- p.28 / Chapter 2.3.3.1 --- The ultra high vacuum chamber (UHV) --- p.28 / Chapter 2.3.3.2 --- The electron gun --- p.28 / Chapter 2.3.3.3 --- The sample --- p.30 / Chapter 2.3.3.4 --- The detector system --- p.30 / Chapter Chapter 3 --- Surface treatments --- p.31 / Chapter 3.1 --- Semiconductor wafers --- p.31 / Chapter 3.2 --- Cleaning procedure --- p.31 / Chapter 3.3 --- Polysulfide passivation --- p.33 / Chapter Chapter 4 --- Gas-phase polysulfide passivation of the InP(100) surface --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Sulfide-assisted reordering at the InP(100) surface --- p.38 / Chapter 4.2.1 --- Gas-phase polysulfide-treated InP( 100) surface --- p.38 / Chapter 4.2.2 --- Further annealing of the gas-phase polysulfide-treated surface --- p.47 / Chapter 4.2.3 --- Comparison with the UV/O3-HF treatment --- p.48 / Chapter 4.2.4 --- Sulfide at the interface of SiNx/InP --- p.49 / Chapter 4.3 --- Conclusions --- p.53 / Chapter Chapter 5 --- Gas-phase polysulfide passivation of the GaAs(lOO) surface --- p.55 / Chapter 5.1 --- Introduction --- p.55 / Chapter 5.2 --- Gas-phase poly sulfide-passivated GaAs( 100) surface --- p.56 / Chapter 5.2.1 --- Surface structure of the as-treated surface --- p.56 / Chapter 5.2.2 --- Surface structure after further annealing --- p.64 / Chapter 5.2.3 --- Mechanism of the gas-phase polysulfide passivation --- p.67 / Chapter 5.3 --- Conclusions --- p.68 / Chapter Chapter 6 --- Gas-phase polysulfide passivation of the GaAs(100) surface --- p.69 / Chapter 6.1 --- Introduction --- p.69 / Chapter 6.2 --- Reordering at the gas-phase polysulfide-passivated GaAs(100) surface --- p.70 / Chapter 6.2.1 --- Adsorption of polysulfide on the GaAs(100) surface --- p.70 / Chapter 6.2.2 --- Ordered sulfide at the GaAs(l 10) surface --- p.73 / Chapter 6.2.3 --- Further analysis of the LEED pattern --- p.80 / Chapter 6.3 --- Conclusions --- p.83 / Chapter Chapter 7 --- Sulfide Solution passivation of the GaAs(100) surface --- p.84 / Chapter 7.1 --- Introduction --- p.84 / Chapter 7.2 --- Sulfide solution passivation on the GaAs(l 10) surface --- p.85 / Chapter 7.2.1 --- Etching of sulfide solution on the GaAs(l 10) surface --- p.85 / Chapter 7.2.2 --- Annealing of sulfide solution-passivated GaAs( 110) surface --- p.88 / Chapter 7.2.3 --- Further analysis of the LEED pattern --- p.92 / Chapter 7.2.4 --- Shift of XPS peak position during annealing --- p.95 / Chapter 7.3 --- Conclusions --- p.97 / Chapter Chapter 8 --- Conclusions and further work --- p.99 / Chapter 8.1 --- Conclusions --- p.99 / Chapter 8.2 --- Further work --- p.100 / References --- p.102

by Lam Siu Dan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 65-67). / Text in English; abstracts in English and Chinese. / by Lam Siu Dan. / Table of contents --- p.I / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Interest in GaAs1-xNx/GaAs alloy --- p.1 / Chapter 1.2 --- Interest in growing GaAs1-xNx/GaAs using different carrier gases --- p.4 / Chapter 1.3 --- Theoretical calculation of the band gap energy of GaAs1-xNx alloy --- p.4 / Chapter 1.4 --- Advantages of using photoluminescence (PL) --- p.7 / Chapter 1.5 --- Our work --- p.9 / Chapter Chapter 2 --- Experimental setup and procedures / Chapter 2.1 --- Growth conditions of GaAs1-xNx on (001) GaAs --- p.10 / Chapter 2.2 --- X-ray diffraction / Chapter 2.2.1 --- Setup --- p.12 / Chapter 2.2.2 --- Types of X-ray measurements --- p.12 / Chapter 2.3 --- PL measurements / Chapter 2.3.1 --- Setup --- p.14 / Chapter 2.3.2 --- Types of PL measurement --- p.16 / Chapter Chapter 3 --- Results and discussions / Chapter 3.1 --- X-ray diffraction of GaAs1-xNx/GaAs / Chapter 3.1.1 --- GaAs1-xNx/GaAs grown using H2 as carrier gas --- p.17 / Chapter 3.1.2 --- GaAs1-xNx/GaAs grown using N2 as carrier gas --- p.28 / Chapter 3.1.3 --- Peak widths of the X-ray rocking curves of GaAs1-xNx/GaAs --- p.30 / Chapter 3.2 --- Room temperature (RT) and 10K PL of GaAs1-xNx/GaAs / Chapter 3.2.1 --- The energy of the NBE peak of GaAs1-xNx/GaAs --- p.32 / Chapter 3.2.2 --- The width of the NBE peak of GaAs1-xNx/GaAs --- p.44 / Chapter 3.3 --- Excitation power density (EPD) dependent PL studies of GaAs1-xNx/GaAs / Chapter 3.3.1 --- The energy of the NBE peak of GaAs1-xNx/GaAs --- p.49 / Chapter 3.3.2 --- The width of the NBE peak of GaAs1-xNx/GaAs --- p.55 / Chapter 3.4 --- Temperature dependent PL studies of GaAs1-xNx/GaAs --- p.57 / Chapter Chapter 4 --- Conclusions --- p.62 / References --- p.63

<p>We study the spin polarization and conductance in infinitely long quasi one-dimensionalquantum wires under various conditions in an attempt to reproduce and to explain some of theanomalous conductance features as seen in various experiments. In order to accomplish thistask we create an idealized model of a quantum wire in a split-gate semiconductorheterostructure and we perform self-consistent Hartree-Fock calculations to determine theelectron occupation and spin polarization. Based on those results we calculate the currentthrough the wire as well as the direct and differential conductances. In the frame of theproposed model the results show a high degree of similarity to some of the experimentallyobserved conductance features, particularly the 0.25- and 0.85-plateaus. These results lead usto the conclusion that those conductance anomalies are in fact caused by the electronsspontaneously polarizing due to electron-electron interactions when an applied potentialdrives a current through the wire.</p>

Graduation date: 1993

This thesis examines the feasibility of using conventional semiconductors, specifically GaAs, as a plasmonic material at the operating wavelength of 1550nm, due to its many merits such as achievable low losses and mature micro-fabrication technologies. A theoretical study is performed on GaAs that yielded the condition for plasmonic behaviour at a minimum free carrier density of 7.2 x 10^20cm^-3 in bulk materials. The most feasible route to achieving this condition is determined to be intense optical excitation, and the required intensity considering a 150fs pulse at the above bandgap wavelength of 870nm is approximately 2.55TW/cm^2. A Bragg reflection ridge waveguide (BRW) using GaAs-AlGaAs is designed and micro-fabricated, and a counter-propagating pump-probe experiment is devised to test the plasmonic effect using the BRW. Results from two different ultrafast lasers include the observation of pump (870nm and 800nm) coupling to fundamental Bragg modes, and the measurement of the pump transmission spectrum.

This thesis examines the feasibility of using conventional semiconductors, specifically GaAs, as a plasmonic material at the operating wavelength of 1550nm, due to its many merits such as achievable low losses and mature micro-fabrication technologies. A theoretical study is performed on GaAs that yielded the condition for plasmonic behaviour at a minimum free carrier density of 7.2 x 10^20cm^-3 in bulk materials. The most feasible route to achieving this condition is determined to be intense optical excitation, and the required intensity considering a 150fs pulse at the above bandgap wavelength of 870nm is approximately 2.55TW/cm^2. A Bragg reflection ridge waveguide (BRW) using GaAs-AlGaAs is designed and micro-fabricated, and a counter-propagating pump-probe experiment is devised to test the plasmonic effect using the BRW. Results from two different ultrafast lasers include the observation of pump (870nm and 800nm) coupling to fundamental Bragg modes, and the measurement of the pump transmission spectrum.

The low thermal conductivity of gallium arsenide compared to silicon results in self-heating effects in GaAs MESFETs that limit the electrical performance of such devices for high power applications. To date, analytical thermal models of self heating in GaAs MESFETs are based on the assumption of a uniformly heated channel. This thesis presents a two dimensional analysis of the electrothermal effect of this device based on the two dimensional power density distribution in the channel under various bias conditions. The numerical simulation is performed using the finite difference technique. The results of the simulation of an isothermal MESFET without heat effects is compared with various one dimensional analytical models in the literature. Electro thermal effects into the two-dimensional isothermal MESFET model allowed close examination of the temperature profile within the MESFET. The large gradient in power distribution results in a localized heat source within the channel which increases the overall channel temperature, which shows that the assumption of a uniformly heated channel is erroneous, and may lead to an underestimation of the maximum channel temperature. / Graduation date: 1992

Present day data processing technology requires very high speed signal processing and data conversion rates. One such application which requires high speed is switched capacitor circuits used in Sigma-Delta modulators. A major active component of switched capacitor circuits is the monolithic operational amplifier(opamp). Because of the relatively poor speed performance of the currently available silicon based technology, such high speed circuits can not be designed. GaAs technology appears to be a promising alternative technology for high speed switched capacitor circuits. One problem with GaAs is the lack of complementary technology. Until now, most of the design of GaAs analog integrated circuits has been implemented using depletion mode n-MESFETs, where operational amplifiers and switched capacitors have been developed by various groups. This thesis develops the techniques for implementation of analog integrated circuits using complementary GaAs Heterojunction Field Effect Transistors(HFETs). Several operational amplifiers have been designed and their performance studied via simulation. The designs studied predict superior high frequency performance for C-HFETs over conventional GaAs MESFET and Silicon CMOS technology. The opamp designs are currently being implemented at Oregon State University for fabrication in the future. / Graduation date: 1993