Solid-state lasers are of great interest and importance in infrared sensing and imaging devices as well as in other applications. The objective of this research was to study the synthesis, crystal growth, and optical characterization of a material recently discovered for its potentially useful optical properties: lanthanum magnesium aluminate (LMA). In these experiments, samples of LMA were grown by the vertical gradient freeze (VGF) technique. This technique has most recently been used to grow high quality titanium doped sapphire crystals mainly due to the inherent stability of this system in providing a stationary heat zone during growth runs. The furnace used for this growth technique also has the advantage of requiring a reducing atmosphere which may be used, if desired, to maintain reduced valence states of the dopant ions. This thesis discusses tunable lasers, crystal growth techniques, and the results of the study on LMA.

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by Wong Ho Man, Bruce. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves [60-61]). / Text in English; abstracts in English and Chinese. / by Wong Ho Man, Bruce. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of Contents --- p.iv / List of figures --- p.vi / Chapter Chapter1 --- Introduction --- p.1 / Chapter Chapter 2 --- Fabrication of erbium-doped sol-gel derived silica --- p.4 / Chapter 2.1 --- Introduction to the sol-gel process --- p.4 / Chapter 2.1.1 --- The procedure for silica formation - ´ؤ --- p.7 / Chapter 2.1.2 --- Changes during the sol-gel process --- p.11 / Chapter 2.2 --- Factors affecting the fluorescence --- p.15 / Chapter 2.2.1 --- Clustering of Er3+ ions in the silica samples --- p.15 / Chapter 2.2.2 --- Retention of hydroxyl group OH/absorbed water in silica - --- p.16 / Chapter 2.3 --- The role of Aluminum in dissolving Er3+ ions in Si02 network --- p.18 / Chapter 2.4 --- Thermal dehydroxylation --- p.20 / Chapter 2.5 --- Characterization of the Erbium-doped silica samples --- p.24 / Chapter 2.5.1 --- Absorption spectrum --- p.24 / Chapter 2.5.2 --- "Refractive index, density and microhardness" --- p.29 / Chapter Chapter 3 --- Fluorescence spectroscopy --- p.35 / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Experimental set-up --- p.36 / Chapter 3.3 --- "Fluorescence spectrum with variation in Er3+ concentration, Al/Er molar ratio and annealing temperature" --- p.38 / Chapter Chapter 4 --- Decay lifetime measurements of the 4S3/2 energy level --- p.47 / Chapter 4.1 --- Introduction --- p.47 / Chapter 4.2 --- Experimental set-up --- p.48 / Chapter 4.3 --- Increase in decay lifetimes with Aluminum-codoping --- p.49 / Chapter Chapter 5 --- Conclusions and further works --- p.58 / References

Ha Kwong-leung = 不同的生長處理對II-VI/III-V外延層的表面、結構和光學特性的影響 / 夏廣良. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 76-79). / Text in English; abstracts in English and Chinese. / Ha Kwong-leung = Bu tong de sheng chang chu li dui II-VI/III-V wai yan ceng de biao mian, jie gou he guang xue te xing de ying xiang / Xia Guangliang. / Acknowledgments --- p.i / Abstract --- p.ii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Brief introduction --- p.1 / Chapter 1.2 --- Background of the epitaxial growth --- p.4 / Chapter 1.3 --- Our work --- p.6 / Chapter Chapter 2 --- Experimental procedures / Chapter 2.1 --- Substrate preparation --- p.7 / Chapter 2.2 --- Metal-organic sources --- p.9 / Chapter 2.3 --- Growth conditions --- p.10 / Chapter Chapter 3 --- Characterization methods / Chapter 3.1 --- Surface morphology --- p.13 / Chapter 3.2 --- X-ray diffraction --- p.14 / Chapter 3.3 --- Optical properties / Chapter 3.3.1 --- Photoluminescence --- p.17 / Chapter 3.3.2 --- General properties of PL spectrum of ZnSe/GaAs --- p.18 / Chapter 3.4 --- Other techniques --- p.21 / Chapter Chapter 4 --- Influence on the properties of epilayers by the thickness of the low-temperature buffer layer --- p.22 / Chapter 4.1 --- Effects on the surface morphology --- p.23 / Chapter 4.2 --- Effects on the structural properties --- p.31 / Chapter 4.3 --- Effects on the optical properties --- p.35 / Chapter Chapter 5 --- Influence of thickness of epilayers on their properties --- p.39 / Chapter 5.1 --- Effects on the surface morphology --- p.40 / Chapter 5.2 --- Effects on the structural properties --- p.45 / Chapter 5.3 --- Effects on the optical properties --- p.50 / Chapter Chapter 6 --- Influence on the epilayers by passivating with different MO sources and different durations of interruption --- p.53 / Part I: Passivation by different MO sources / Chapter 6.1 --- Effects on the surface morphology --- p.55 / Chapter 6.2 --- Effects on the structural properties --- p.58 / Chapter 6.3 --- Effects on the optical properties --- p.61 / Part II: Different durations of interruption / Chapter 6.4 --- Effects on the surface morphology --- p.63 / Chapter 6.5 --- Effects on the structural properties --- p.66 / Chapter 6.6 --- Effects on the optical properties --- p.70 / Summary --- p.73 / Conclusions --- p.74 / References --- p.76

Choy Kwok Wai = 利用全光極化在本體聚合物中產生準相匹配二次諧波 / 蔡國偉. / Thesis submitted in: August 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 132-133). / Text in English; abstracts in English and Chinese. / Choy Kwok Wai = Li yong quan guang ji hua zai ben ti ju he wu zhong chan sheng zhun xiang pi pei er ci xie bo / Cai Guowei. / Acknowledgements --- p.ii / Abstract --- p.iii / Chinese Abstract --- p.V / Table of Contents --- p.vi / List of Figures --- p.ix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Principle and origin of nonlinear optics --- p.2 / Chapter 1.2 --- Tensor properties and Inversion symmetry --- p.3 / Chapter 1.3 --- Relationship between microscopic and macroscopic nonlinear susceptibility for a poled polymer --- p.5 / Chapter 1.4 --- Second Harmonic Generation by nonlinear polarization --- p.7 / Chapter 1.5 --- Outline of the thesis --- p.9 / Figures --- p.10 / Chapter Chapter 2 --- Poling and relaxation of nonlinear optical polymeric systems --- p.11 / Chapter 2.1 --- Guest-Host nonlinear optical polymeric systems --- p.11 / Chapter 2.2 --- Poling techniques --- p.13 / Chapter 2.2.1 --- Thermal-assisted Electric Poling --- p.13 / Chapter 2.2.2 --- Photo-assisted Electric Poling --- p.15 / Chapter 2.2.3 --- All-optical Poling --- p.17 / Chapter 2.3 --- Quasi-phase-matching in bulk polymers by All-optical Poling --- p.20 / Chapter 2.4 --- Photorefractive effect in polymers --- p.22 / Chapter 2.5 --- Relaxation study of NLOP system --- p.23 / Figures --- p.27 / Chapter Chapter 3 --- Experimental Method --- p.33 / Chapter 3.1 --- Experimental Setup --- p.33 / Chapter 3.1.1 --- Laser system --- p.33 / Chapter 3.1.2 --- Data acquisition system --- p.34 / Chapter 3.1.3 --- Reference arm --- p.34 / Chapter 3.1.4 --- Optical Path --- p.35 / Chapter 3.2 --- Sample Preparation --- p.36 / Chapter 3.2.1 --- Polymer Films Preparation --- p.36 / Chapter 3.2.2 --- Bulk Polymers Preparation --- p.38 / Chapter 3.3 --- Poling and Thermal history of samples --- p.41 / Figures --- p.43 / Chapter Chapter 4 --- Growth and decay of optical nonlinearity in all-optically poled polymers --- p.53 / Chapter 4.1 --- Poling profiles for DR-1 and DANS doped bulk polymer by All-optical poling --- p.53 / Chapter 4.1.1 --- Poling profiles for DR-1 doped bulk polymer and polymer films by All-optical poling --- p.53 / Chapter 4.1.2 --- Possibilities of degradation of the samples during the experiment --- p.56 / Chapter 4.1.3 --- Effects of probing beam intensity and the duration of probing on the growth and decay of X(2) --- p.57 / Chapter 4.1.4 --- Poling profiles for DANS doped bulk polymer by All-optical poling --- p.57 / Chapter 4.2 --- Dependence of the poling profiles on various parameters in all-optical poling --- p.59 / Chapter 4.2.1 --- Dependence on the temperature --- p.59 / Chapter 4.2.2 --- Dependence on the relative intensities between the two seeding beams --- p.60 / Chapter 4.2.3 --- Dependence on the relative phase between the two seeding beams --- p.64 / Chapter 4.2.4 --- Tensorial properties of X(2) --- p.67 / Chapter 4.2.5 --- Dependence on the thickness of the sample --- p.68 / Chapter 4.3 --- Comparison of different relaxation models --- p.69 / Figures --- p.71 / Chapter Chapter 5 --- Growth and decay of optical nonlinearity in poled polymers with charge-generating additives --- p.89 / Chapter 5.1 --- Orientational enhancement in NLOP systems --- p.89 / Chapter 5.2 --- Space-charge field by charge-transporting molecules and sensitizer --- p.89 / Chapter 5.3 --- Poling profile of the bulk DR-1 polymer with charge-generating ingredients --- p.91 / Chapter 5.4 --- Poling profile of the bulk DANS polymer with the presence of charge-transporting molecules and sensitizers --- p.100 / Figures --- p.107 / Chapter Chapter 6 --- Growth and decay of optical nonlinearity in a nano-structured composite system --- p.113 / Chapter 6.1 --- Historical background --- p.113 / Chapter 6.2 --- Preparation of the composites films --- p.116 / Chapter 6.2.1 --- Preparation of the silver nano-particles --- p.116 / Chapter 6.2.2 --- Preparation of the composite films --- p.117 / Chapter 6.3 --- Poling profiles of polymer films with silver nano-particles --- p.118 / Figures --- p.124 / Chapter Chapter 7 --- Conclusions --- p.129 / References --- p.132

Lai Chung Wing = 金屬膜覆蓋在氧化鋅上之光學變化 / 黎頌榮. / Thesis submitted in: July 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Lai Chung Wing = Jin shu mo fu gai zai yang hua xin shang zhi guang xue bian hua / Li Songrong. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of contents --- p.iv / List of Figures --- p.vi / Chapter Chapter 1 --- Introduction / Chapter 1.1. --- Motivation --- p.1-1 / Chapter 1.2. --- Literature Review --- p.1-2 / Chapter 1.3. --- Our Study --- p.1-4 / References --- p.1-6 / Chapter Chapter 2 --- Methodology and Experiments / Chapter 2.1. --- RF sputtering --- p.2-1 / Chapter 2.1.1. --- Setup of RF sputtering --- p.2-2 / Chapter 2.1.2. --- Sample preparation --- p.2-3 / Chapter 2.2. --- Scanning electron Microscope --- p.2-4 / Chapter 2.3. --- Cathodoluminescence --- p.2-5 / Chapter 2.3.1. --- Background of CL --- p.2-6 / Chapter 2.3.2. --- Room temperature CL studies --- p.2-7 / Chapter 2.3.3. --- Software: Casino --- p.2-8 / Chapter 2.3.4. --- Depth resolved CL studies --- p.2-10 / Chapter 2.3.5. --- Power dependent CL studies --- p.2-11 / Chapter 2.4. --- Photoluminescence / Chapter 2.4.1. --- General background of PL --- p.2-11 / Chapter 2.4.2. --- Room temperature PL studies --- p.2-12 / Chapter 2.4.3. --- Quantum efficiency measurement --- p.2-13 / Chapter 2.5. --- Optical transmission measurement --- p.2-13 / References --- p.2-15 / Chapter Chapter 3 --- Experimental Results and Data Analysis / Chapter 3.1. --- Study of Optical emissions of bare and Au-capped ZnO --- p.3-1 / Chapter 3.1.1. --- RT-luminescence of ZnO --- p.3-1 / Chapter 3.1.2. --- RT- Luminescence of Au- capped ZnO films --- p.3-2 / Chapter 3.2. --- RT-luminescence of metal capped ZnO --- p.3-7 / Chapter 3.3. --- Power dependent and depth Resolved CL --- p.3-10 / Chapter 3.3.1. --- Dependence of the CL on beam energy --- p.3-10 / Chapter 3.3.2. --- Dependence of the CL intensity on beam energy --- p.3-13 / Chapter 3.4. --- Dependence of metal thickness on the RT- luminescence --- p.3-17 / References --- p.3-19 / Chapter Chapter 4 --- Discussions / Chapter 4.1. --- General discussions --- p.4-1 / Chapter 4.2. --- Surface recombination Velocity / Chapter 4.2.1. --- Quantum Efficiency --- p.4-2 / Chapter 4.2.2. --- Simulation of the dependence of surface recombination velocity on the CL intensity of ZnO --- p.4-5 / Chapter 4.3. --- Effects of metallization on MgZnO/ZnO bilayer --- p.4-10 / Chapter 4.4. --- Surface plasmon --- p.4-13 / Chapter 4.5. --- PL measurement from the backside of substrate --- p.4-18 / Chapter 4.5.1. --- Au and Ag coating by sputtering --- p.4-19 / Chapter 4.5.2. --- Au and Ag coating by thermal evaporation --- p.4-21 / Chapter 4.6. --- Au coating spaced by MgO --- p.4-23 / Chapter 4.7. --- Optical transmission of Au-capped ZnO --- p.4-25 / Chapter 4.8. --- Cross Section images by AFM and TEM --- p.4-27 / Chapter 4.9. --- Application: optical improvement of semiconductor --- p.4-30 / Chapter 4.10. --- Summary --- p.4-32 / References --- p.4-34 / Chapter Chapter 5 --- Conclusions --- p.5-1 / Appendix I --- p.A / Appendix II --- p.K

Song Liang = 向列液晶中激光束感应的取向重联非线性光学效应和取向性光折变光栅形成 / 宋亮. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Song Liang = Xiang lie ye jing zhong ji guang shu gan ying de qu xiang zhong lian fei xian xing guang xue xiao ying he qu xiang xing guang zhe bian guang zha xing cheng / Song Liang. / Abstract --- p.i / 论文摘要 --- p.iii / Acknowledgement --- p.iv / Contents --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / References --- p.5 / Chapter Chapter 2 --- Brief review of liquid crystals and nonlinear optics of liquid crystals --- p.9 / Chapter 2.1 --- Brief review of liquid crystals --- p.9 / Chapter 2.1.1 --- General description --- p.9 / Chapter 2.1.2 --- Types of liquid crystals --- p.11 / Chapter 2.1.3 --- Order parameter --- p.14 / Chapter 2.1.4 --- Liquid crystal alignment --- p.14 / Chapter 2.1.5 --- Continuum theory of liquid crystals --- p.16 / Chapter 2.2 --- Nonlinear optics of liquid crystals --- p.20 / Chapter 2.2.1 --- Basic mechanism of nonlinear optics --- p.20 / Chapter 2.2.2 --- Self-phase modulation --- p.23 / Chapter 2.2.3 --- Orientational photorefractive effects --- p.29 / Chapter 2.3 --- Sample preparation --- p.34 / Chapter 2.4 --- Conclusion --- p.37 / References --- p.39 / Chapter Chapter 3 --- Domain formation in homeotropic nematic liquid crystal cell --- p.42 / Chapter 3.1 --- Introduction --- p.42 / Chapter 3.2 --- Domain formation under applied dc and ac electric fields --- p.44 / Chapter 3.3 --- Light scattering of domains under applied dc and ac electric fields --- p.49 / Chapter 3.4 --- Conclusion --- p.53 / References --- p.54 / Chapter Chapter 4 --- Laser induced self-phase modulation and effects of applied electric field --- p.56 / Chapter 4.1 --- Introduction --- p.56 / Chapter 4.2 --- Self-phase modulation without applied electric field --- p.58 / Chapter 4.2.1 --- Experimental setup --- p.58 / Chapter 4.2.2 --- Experimental results and discussions --- p.59 / Chapter 4.3 --- Effects of applied electric field --- p.67 / Chapter 4.3.1 --- Effects of applied dc electric field --- p.67 / Chapter 4.3.2 --- Effects of applied ac electric field --- p.72 / Chapter 4.4 --- Conclusion --- p.75 / References --- p.77 / Chapter Chapter 5 --- Orientational photorefractive grating in nematic liquid crystals --- p.80 / Chapter 5.1 --- Introduction --- p.80 / Chapter 5.2 --- Orientational photorefractive grating under dc electric field --- p.82 / Chapter 5.2.1 --- Experimental setup --- p.82 / Chapter 5.2.2 --- Experimental results and discussion --- p.84 / Chapter 5.3 --- Orientational photorefractive grating under ac electric field --- p.90 / Chapter 5.3.1 --- Raman-Nath grating --- p.90 / Chapter 5.3.2 --- Quasi-Bragg grating --- p.96 / Chapter 5.4 --- Conclusion --- p.98 / References --- p.100 / Chapter Chapter 6 --- Summary and future outlook --- p.103 / List of Publications and Conference Presentations --- p.107

Chen Ji = 由純淨有機物質及其混合物產生的具有退極化性質的超瑞利散射的光譜研究 / 陳佶. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 91-92). / Text in English; abstracts in English and Chinese. / Chen Ji = You chun jing you ji wu zhi ji qi hun he wu chan sheng de ju you tui ji hua xing zhi de chao Ruili san she de guang pu yan jiu / Chen Ji. / Abstract --- p.i / Chhiese Abstract --- p.ii / Acknowledgments --- p.iii / Table of Contents --- p.iv / List of Figures and Tables --- p.vii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Basic Theory --- p.5 / Chapter 2.1 --- A brief introduction to nonlinear optics --- p.5 / Chapter 2.2 --- Second Harmonic Generation (SHG) --- p.7 / Chapter 2.3 --- Hyper Rayleigh Scattering (HRS) --- p.9 / Chapter 2.4 --- Comparison between Second Harmonic Generation and Hyper Rayleigh Scattering --- p.10 / Chapter 2.5 --- HRS signal from a liquid --- p.12 / Chapter 2.6 --- Methods for measuring hyperpolarizability βby HRS --- p.13 / Chapter 2.7 --- Theoretical description of the depolarization ratio in HRS for a rod-like molecule --- p.16 / Chapter 2.8 --- Organic molecules with strong quadratic nonlinearities --- p.20 / Chapter Chapter 3 --- Experimental Setup --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Detailed descriptions of the main componets --- p.27 / Chapter 3.2.1 --- Laser system --- p.27 / Chapter 3.2.2 --- Scattered light collection system --- p.29 / Chapter 3.2.3 --- Data acquisition system --- p.32 / Chapter 3.3 --- Basic performance tests of the experimental setup --- p.35 / Chapter 3.3.1 --- Temporal stability of the apparatus --- p.35 / Chapter 3.3.2 --- Linearity of the light detection apparatus --- p.36 / Chapter 3.3.3 --- Background noise --- p.38 / Chapter 3.4 --- Sample preparation --- p.40 / Chapter Chapter 4 --- General spectral measurements and measurement of hyperpolarizability β for some organic chemicals --- p.41 / Chapter 4.1 --- Low and high resolution HRS spectra of several common liquids --- p.41 / Chapter 4.2 --- Experimental performance test of HRS by using PNA solution --- p.45 / Chapter 4.3 --- Measurements of the first order hyperpolarizability b for Crystal Violet (CV) by a modified Internal Reference Method (IRM) --- p.50 / Chapter 4.3.1 --- Basic spectral measurement of CV --- p.50 / Chapter 4.3.2 --- Measurement of hyperpolarizability β for CV --- p.52 / Chapter Chapter 5 --- Study of coherent and incoherent hyper-Rayleigh scattering for organic chemicals --- p.57 / Chapter 5.1 --- Introduction --- p.57 / Chapter 5.2 --- Calibration of the experimental setup --- p.59 / Chapter 5.3 --- "Study of depolarization ratio of PNA solution, Nitrobenzene and CCl4" --- p.64 / Chapter 5.4 --- Further study of depolarization ratio for Nitrobenzene and its mixtures --- p.68 / Chapter 5.5 --- More studies on depolarization ratios for CC14 and Nitrobenzene --- p.79 / Chapter 5.6 --- "Spectral study of PNA solution, Nitrobenzene and its mixtures" --- p.83 / Chapter 5.7 --- Summary --- p.85 / Chapter Chapter 6 --- Conclusions --- p.88 / References --- p.91

從上世紀80年代中期開始，矽光子學在研究與工業界都有快速的發展。矽光子學有望實現電子與光子電路的一體化集成，從而使得光電子系統的價格和能耗大大地降低。基於這樣的特性，矽光子學被提出用於當前的光通信系統。 / 在這篇論文中，我們將研究矽波導在光信號的成型和重定時中的應用。首先，我們研究基於自由載流子色散效應的矽調製器。調製器的原理和設計方法將會詳細地討論。我們所設計的調製器是基於馬赫-曾德爾干涉儀。實驗表明，製作好的調製器的3dB電光帶寬達到了5GHz。當調製器進行非歸零開關鍵控調製時，調製器的速率可以達到12.45GHz，且誤碼率在10⁻⁹以下。同時，調製器用於正交頻分複用調製格式的結果也會給出。接著，我們研究矽波導中產生的四波混頻效應如何增強信號消光比和減少時域抖動。我們通過實驗表明了，矽波導中的四波混頻效應可以增強單通道的10和40Gb/s歸零開關鍵控信號的消光比。我們接著將四波混頻效應應用於時域交叉的雙通道歸零開關鍵控信號。實驗結果也表明，兩個通道的消光比都能得到增強。我們也通過實驗表明，四波混頻效應可以減少10Gb/s歸零開關鍵控信號的時域抖動。最後，我們用矽波導和chirped光纖光栅實現了一套可調光延遲系統。當這套系統分別應用於10Gb/s的光脈衝、非歸零開關監控信號和歸零的差分相位鍵控信號時，延遲效果都一致。 / Emerging from the mid-1980s, the field of silicon photonics has been rapidly growing, in both research and industry. Silicon photonics has the great potential of monolithic integration of both electronic and photonic circuits. With monolithic integration, the cost and power consumption of photonic systems can be cut down greatly. Due to these features, silicon photonics is proposed for applications in today’s optical communication systems. / In this thesis, silicon waveguide devices for shaping and retiming of optical signals will be investigated. Firstly, silicon Mach-Zehnder modulators based on free-carrier plasma dispersion effect are explored for amplitude modulation of optical signals. The principle and design of the modulators are discussed in details. Experimental results show that 3 dB electro-optic bandwidth of the modulators is 5 GHz, while 10⁻⁹ bit error rate can be obtained for up to 12.45 Gb/s modulated non-return-to-zero (NRZ) on-off keying (OOK) signal. Also, the results of the modulators for orthogonal frequency division multiplexing modulation will be given. Then, silicon waveguides are used as nonlinear medium of four-wave mixing (FWM) effect for extinction ratio enhancement and timing jitter reduction of optical signals. Extinction ratio enhancement of single channel 10 and 40 Gb/s return-to-zero (RZ) OOK signal is experimentally demonstrated. Following that we extend the scheme for two 40 Gb/s RZ-OOK channels which are time-interleaved and obtain extinction ratio enhancement for both. Timing jitter reduction of 10 Gb/s RZ-OOK signal is also achieved by FWM effect in silicon waveguides. Finally, a tunable delay line incorporating a silicon waveguide and a chirped fiber Bragg grating is realized for timing alignment of optical signals. The tunable delay line is used for 10 Gb/s optical pulse, NRZ-OOK signal and RZ differential phase-shift keying (DPSK) signal, showing consistent performance for all. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Yimin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Abstracts also in Chinese. / Acknowledgements --- p.ii / Abstract --- p.iv / Table of Contents --- p.vii / List of Tables --- p.x / List of Figures --- p.xi / Chapter Chapter 1 --- Introduction --- p.17 / Chapter 1.1 --- Research context --- p.17 / Chapter 1.2 --- Waveguides and modulators in silicon photonics --- p.18 / Chapter 1.2.1 --- Silicon photonics --- p.20 / Chapter 1.2.2 --- Silicon modulator --- p.23 / Chapter 1.2.3 --- Silicon waveguide as nonlinear medium --- p.24 / Chapter 1.3 --- Purpose and outline of this work --- p.26 / References --- p.26 / Chapter Chapter 2 --- Silicon modulators for optical communications --- p.28 / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.1.1 --- Motivation for high capacity transmission system --- p.28 / Chapter 2.1.2 --- Literature review of silicon modulators --- p.30 / Chapter 2.2 --- Design of silicon modulators --- p.38 / Chapter 2.2.1 --- Optical circuit of silicon modulators --- p.38 / Chapter 2.2.2 --- p-n junction --- p.43 / Chapter 2.2.3 --- Electronic circuit --- p.44 / Chapter 2.3 --- Fabrication process --- p.46 / Chapter 2.4 --- Experimental results --- p.47 / Chapter 2.4.1 --- Testing results --- p.48 / Chapter 2.4.2 --- OFDM modulation --- p.58 / Chapter 2.5 --- Summary --- p.61 / References --- p.64 / Chapter Chapter 3 --- Signal quality enhancement using four-wave mixing in silicon waveguides --- p.68 / Chapter 3.1 --- Introduction --- p.68 / Chapter 3.1.1 --- All-optical wavelength conversion and all-optical regeneration --- p.68 / Chapter 3.1.2 --- Generic basics of four-wave mixing --- p.69 / Chapter 3.1.3 --- Four-wave mixing in silicon waveguides --- p.71 / Chapter 3.2 --- Extinction ratio enhancement using FWM in a silicon waveguide --- p.77 / Chapter 3.2.1 --- Extinction ratio enhancement of 10 and 40 Gb/s RZ-OOK signals --- p.77 / Chapter 3.2.1.1 --- Principle --- p.78 / Chapter 3.2.1.2 --- Experimental setup and results --- p.78 / Chapter 3.2.1.3 --- Discussion --- p.82 / Chapter 3.2.2 --- Extinction ratio enhancement of two 40 Gb/s RZ-OOK channels --- p.82 / Chapter 3.2.2.1 --- Principle --- p.83 / Chapter 3.2.2.2 --- Experimental setup and results --- p.84 / Chapter 3.2.2.3 --- Discussion --- p.89 / Chapter 3.3 --- Timing jitter reduction using FWM in silicon waveguides --- p.90 / Chapter 3.3.1 --- Principle --- p.91 / Chapter 3.3.2 --- Experimental setup and results --- p.92 / Chapter 3.3.2.1 --- Timing jitter reduction of RZ-OOK signal --- p.92 / Chapter 3.3.2.2 --- Timing jitter reduction of AMI signal --- p.96 / Chapter 3.3.3 --- Discussion --- p.101 / Chapter 3.4 --- Summary --- p.102 / References --- p.103 / Chapter Chapter 4 --- Optical tunable delay line incorporating a silicon waveguide and a chirped fiber Bragg grating --- p.106 / Chapter 4.1 --- Introduction --- p.106 / Chapter 4.1.1 --- Motivation --- p.106 / Chapter 4.1.2 --- Principle --- p.107 / Chapter 4.1.3 --- Characteristics of the silicon waveguide and chirped FBG --- p.108 / Chapter 4.2 --- Tunable delay line for 10 Gb/s optical signals --- p.111 / Chapter 4.2.1 --- 10 Gb/s optical pulse chain --- p.111 / Chapter 4.2.1.1 --- Experimental setup and results --- p.111 / Chapter 4.2.2 --- 10 Gb/s NRZ-OOK signal --- p.115 / Chapter 4.2.2.1 --- Experimental setup and results --- p.115 / Chapter 4.2.3 --- 10 Gb/s RZ-DPSK signal --- p.119 / Chapter 4.2.3.1 --- Experimental setup and results --- p.119 / Chapter 4.3 --- Summary --- p.124 / References --- p.126 / Chapter Chapter 5 --- Conclusions and future work --- p.129 / Chapter 5.1 --- Conclusions --- p.129 / Chapter 5.2 --- Future work --- p.131 / Chapter Appendix A. --- List of Symbols --- p.133 / Chapter Appendix B. --- Abbreviations --- p.135 / Chapter Appendix C. --- Publications --- p.139