As an effective compact coherent light source, distributed feedback (DFB) waveguide laser has attracted much attention recently. Sol-gel Mass synthesized at low temperatures is a very useful optical material. DFB waveguide lasers based on sol-gel glasses were experimentally and theoretically investigated in this thesis. In addition, microring lasers based on a conjugated polymer, which is emerging as an important class of laser material, were also studied in this thesis. / DFB lasing characteristics of various dyes in zirconia waveguides and in solutions were investigated. Intensity modulation and polarization modulation were used to generate the laser action. The laser output showed different polarization characteristics and threshold energy variation when the feedback mechanism was changed from intensity modulation to polarization modulation. In addition, near infrared (NIR) wide-band tuning DFB lasing operation was achieved in NIR dve-doped sol-gel waveguides by using intensity modulation. / Microring cavities were fabricated by depositing poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) (MEH-PPV) on glass fibers by a dip coating method. Laser emissions in whispering gallery modes using microring cavities were observed by pumping with a frequency-doubled Nd:YAG laser. The threshold energy of the MEH-PPV microring laser was as low as 10 nJ per pulse. The polarization characteristics of the microring lasers were studied and a polarization model was developed to explain the observed phenomena. / Theoretical expressions for the angle-dependent coupling coefficients of DFB lasers were derived to explain the polarization properties of the DFB lasers. The coupling and gain coefficients of the two orthogonal polarization components of DFB lasers are strongly dependent on the intersection angle and the polarization states of the two crossing pump heams. The experimental results of DFB lasing in dye solutions have verified our theoretical predictions. / Titania zirconia organically modified silicate (TiO2-ZrO 2-ORMOSIL) DFB waveguide lasers were demonstrated. The output polarization and output wavelength of TiO2-ZrO2-ORMOSIL DFB waveguide lasers were found to be dependent on the polarization of the crossing pump beams from a frequency-doubled Nd:YAG laser. Up to sixteen Output wavelengths corresponding to eight pairs of polarized output from eight propagation modes were observed simultaneously for a planar waveguide with a thickness of 6.7 mum. / Two-photon-pumped DFB lasing action with a narrow linewidth output was demonstrated in zirconia waveguides doped with trans-4-[p-( N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate a compound that shows strong two-photon upconverted emission around 620 nm. Transient gratings for coherent scattering were generated in the waveguides by crossing two 1.06 mum beams. DFB laser emission with the linewidth as narrow as 60 pm was observed. Operating at the third-order Bragg condition, tunable TE mode laser emission was achieved from 618 to 640 nm. TM output modes from the DFB laser were observed when the crossing beams were changed from s-polarized to p-polarized. / Wang Jun = 分佈反饋波導激光器的實驗與理論研究 / 王俊. / "September 2006." / Adviser: King Young Wong. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1702. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 165-183). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307. / Wang Jun = Fen bu fan kui bo dao ji guang qi de shi yan yu li lun yan jiu / Wang Jun.

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

Chen Fei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 86-92). / Abstracts in English and Chinese. / Acknowledgements --- p.i / List of publications --- p.ii / Abstract (In English) --- p.iii / Abstract (In Chinese) --- p.v / Table of contents --- p.vii / List of figures --- p.x / List of tables --- p.xiv / Chapter Chapter I --- Introduction --- p.1 / Chapter Chapter II --- Sol-gel channel waveguides --- p.6 / Chapter 2.1 --- General sol-gel process --- p.6 / Chapter 2.2 --- Dye-doped sol-gel zirconia and zirconia-ORMOSIL materials --- p.10 / Chapter 2.3 --- Fabrication of sol-gel channel waveguides --- p.15 / Chapter 2.3.1 --- General process of the photolithographic technique --- p.15 / Chapter 2.3.2 --- Channels in glass substrates by using photolithographic wet etching technique --- p.19 / Chapter 2.3.3 --- Channels in fused silica substrates by using photolithographic dry etching technique (Inductive-coupled plasma etching) --- p.24 / Chapter Chapter III --- Coupled-wave theory and experimental setup of distributed feedback channel waveguide lasers --- p.27 / Chapter 3.1 --- Coupled-wave theory of distributed feedback lasers --- p.27 / Chapter 3.2 --- Experimental setup --- p.33 / Chapter Chapter IV --- One-dimensional and two-dimensional optical waveguide analysis --- p.37 / Chapter 4.1 --- 1-D planar waveguide analysis --- p.37 / Chapter 4.2 --- 2-D channel waveguide analysis using the Marcatili method --- p.39 / Chapter 4.2.1 --- The Eypq modes: Polarization in the y direction --- p.42 / Chapter 4.2.2 --- The Eypq modes: Polarization in the x direction --- p.46 / Chapter 4.3 --- 2-D channel waveguide analysis using the effective index method --- p.48 / Chapter Chapter V --- Distributed feedback channel waveguide lasers tunable in the visible --- p.50 / Chapter 5.1 --- Rhodamine 6G-doped zirconia planar and channel waveguides --- p.51 / Chapter 5.2 --- Results and discussion --- p.56 / Chapter 5.3 --- Summary --- p.66 / Chapter Chapter VI --- Near infrared distributed feedback channel waveguide lasers --- p.68 / Chapter 6.1 --- LDS dye-doped zirconia-ORMOSIL planar and channel waveguides --- p.68 / Chapter 6.2 --- Results and discussion --- p.72 / Chapter 6.3 --- Summary --- p.80 / Chapter Chapter VII --- Summary --- p.81 / References --- p.86

Chan Jacklynn = 摻近紅外染料溶凝膠薄膜之光學及激光性質研究 / 陳在琳. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 137-152). / Text in English; abstracts in English and Chinese. / Chan Jacklynn = Shan jin hong wai ran liao rong ning jiao bo mo zhi guang xue ji ji guang xing zhi yan jiu / Chen Zailin. / Abstract --- p.i / Acknowledgements --- p.v / Publications --- p.vii / Table of Contents --- p.viii / List of Figures --- p.xi / List of Tables --- p.xiv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Sol-gel Glass Waveguides --- p.3 / Chapter 1.2 --- Ellipsometry --- p.7 / Chapter 1.3 --- Aim of this Research Work and Organization of Thesis --- p.12 / Chapter 2 --- Basics on Ellipsometry --- p.16 / Chapter 2.1 --- Principle of Ellipsometry --- p.17 / Chapter 2.1.1 --- Definition of Ellipsometric Parameters --- p.17 / Chapter 2.1.2 --- Configurations of an Ellipsometer --- p.22 / Chapter 2.2 --- Mathematical Representation of Ellipsometry --- p.26 / Chapter 2.2.1 --- Bulk Material Structure --- p.26 / Chapter 2.2.2 --- Single Layer Structure --- p.28 / Chapter 2.3 --- Parameterization of Optical Functions --- p.31 / Chapter 2.3.1 --- Optical Functions --- p.34 / Chapter 2.3.2 --- Regression Analysis --- p.38 / Chapter 3 --- Modification of Rotating-Polarizer-Analyzer Ellipsometer --- p.40 / Chapter 3.1 --- Principle of RPA System --- p.41 / Chapter 3.2 --- Optical Setup of RPA System --- p.45 / Chapter 3.3 --- Components of the System and Modification for Infrared Measurement --- p.47 / Chapter 3.3.1 --- Light Source --- p.47 / Chapter 3.3.2 --- Monochromator --- p.52 / Chapter 3.3.3 --- Polarizers and Analyzer --- p.53 / Chapter 3.3.4 --- Detector and Data Reduction --- p.54 / Chapter 3.4 --- Optical Alignment --- p.59 / Chapter 3.5 --- Alignment of the Azimuthal Angles of the Polarizers --- p.61 / Chapter 3.6 --- Calibration Procedure --- p.63 / Chapter 3.6.1 --- Calibration by Gold Film on Silicon --- p.63 / Chapter 3.6.2 --- Calibration by Silicon Dioxide Film on Silicon --- p.67 / Chapter 4 --- Near Infrared Dyes in Sol-gel Waveguides --- p.72 / Chapter 4.1 --- Sol-gel Process --- p.73 / Chapter 4.2 --- Near Infrared Dyes in Sol-gel Waveguides --- p.77 / Chapter 4.2.1 --- Development of Near Infrared Dyes --- p.77 / Chapter 4.2.2 --- Studies on Near Infrared Dye Solid State Laser --- p.79 / Chapter 5 --- Optical Properties of Dye-doped Sol-gel Waveguides --- p.83 / Chapter 5.1 --- Experimental Procedure --- p.84 / Chapter 5.1.1 --- Preparation of Samples --- p.84 / Chapter 5.1.1.1 --- Materials --- p.84 / Chapter 5.1.1.2 --- Procedure --- p.86 / Chapter 5.1.2 --- Discussion on Synthesis of Infrared Dye-doped Sol-gel Waveguides --- p.88 / Chapter 5.1.2.1 --- Choice of Solvents --- p.89 / Chapter 5.1.2.2 --- Thermal Treatment and Lifetime --- p.93 / Chapter 5.1.2.3 --- Necessity of Addition of GLYMO --- p.94 / Chapter 5.1.3 --- Sample Characterization --- p.96 / Chapter 5.2 --- Surface Morphology --- p.97 / Chapter 5.3 --- Optical Properties of Dye-doped Zirconia Organically Modified Silicate Waveguides --- p.100 / Chapter 5.3.1 --- Modeling of Ellipsometric Values --- p.101 / Chapter 5.3.2 --- Interpretation of the Modeling Results --- p.107 / Chapter 6 --- Amplified Spontaneous Emission Based on Sol-gel Waveguides --- p.109 / Chapter 6.1 --- Experimental Setup --- p.110 / Chapter 6.2 --- Features of ASE and Fluorescence --- p.112 / Chapter 6.3 --- Prolonged Thermal Treatment Effect on Light Emission --- p.119 / Chapter 6.3.1 --- Difference in Preparation of Samples --- p.121 / Chapter 6.3.2 --- Light Emission of Samples under Extended Thermal Treatment --- p.123 / Chapter 6.3.3 --- Directionality of the Emission --- p.125 / Chapter 6.3.4 --- Some Features of the Emission --- p.127 / Chapter 7 --- Conclusion and Recommendation --- p.133 / Chapter 7.1 --- Conclusion --- p.133 / Chapter 7.2 --- Recommendation --- p.135 / Bibliography --- p.137

Wang Jun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 74-79). / Abstracts in English and Chinese. / Acknowledgements --- p.i / List of publications --- p.ii / Abstract (In English) --- p.iii / Abstract (In Chinese) --- p.v / Table of contents --- p.vii / List of figures --- p.x / List of tables --- p.xiv / Chapter Chapter I --- Introduction --- p.1 / Chapter Chapter II --- Dye-doped sol-gel zirconia and zirconia-organically modified silicate waveguides --- p.6 / Chapter 2.1 --- General sol-gel process --- p.6 / Chapter 2.2 --- Dye-doped sol-gel zirconia and zirconia-ORMOSIL waveguides --- p.7 / Chapter Chapter III --- Basic theory and experiment setup of distributed feedback waveguide lasers --- p.13 / Chapter 3.1 --- Coupled-wave theory of distributed feedback lasers --- p.13 / Chapter 3.2 --- Introduction on the theory of planar optical waveguide --- p.16 / Chapter 3.3 --- Experiment setup design of DFB waveguide lasers --- p.19 / Chapter Chapter IV --- Zirconia and zirconia-organically modified silicate distributed feedback waveguide lasers tunable in the visible --- p.23 / Chapter Chapter V --- Tunable multi-wavelength distributed feedback zirconia waveguide lasers --- p.35 / Chapter 5.1 --- Brief introduction on multi-wavelength lasers --- p.35 / Chapter 5.2 --- R6G-doped zirconia multi-mode waveguides --- p.36 / Chapter 5.3 --- Experimental results and discussion --- p.39 / Chapter 5.3.1. --- Dual- and quadruple-wavelength DFB waveguide lasers --- p.39 / Chapter 5.3.2. --- The dispersion characteristics of multi-wavelength DFB waveguide lasers --- p.44 / Chapter 5.3.3. --- Determination of waveguide parameters by the DFB technique --- p.48 / Chapter 5.4 --- Summary --- p.51 / Chapter Chapter VI --- Distributed feedback laser action in sol-gel glass symmetric waveguides --- p.53 / Chapter 6.1 --- The fabrication of dye-doped glass symmetric waveguides --- p.54 / Chapter 6.2 --- Experimental results and discussion --- p.56 / Chapter 6.2.1. --- DFB laser action in sol-gel glass symmetric-asymmetric waveguide --- p.56 / Chapter 6.2.2. --- Dispersion characteristics of DFB symmetric and asymmetric waveguide lasers --- p.61 / Chapter 6.3 --- Summary --- p.65 / Chapter Chapter VII --- Summary --- p.69 / References --- p.74

The growing speed and bandwidth requirements of telecommunication systems demand all-optical on-chip solutions. Microphotonic devices can deliver low power nonlinear signal processing solutions. This thesis looks at the slow light photonic crystals in chalcogenide glasses to enhance low power nonlinear operation. I demonstrate the development of new fabrication techniques for this delicate class of materials. Both, reactive ion etching and chemically assisted ion beam etching are investigated for high quality photonic crystal fabrication. A new resist-removal technique was developed for the chemical, mechanical and light sensitive thin films. I have developed a membraning method based on vapor phase etching in combination with the development of a save and economical etching tool that can be used for a variety of vapour phase processes. Dispersion engineered slow light photonic crystals in Ge₃₃As₁₂Se₅₅ are designed and fabricated. The demonstration of low losses down to 21±8dB/cm is a prerequisite for the successful demonstration of dispersion engineered slow light waveguides up to a group index of around n[subscript(g)] ≈ 40. The slow light waveguides are used to demonstrate highly efficient third harmonic generation and the first advantages of a pure chalcogenide system over the commonly used silicon. Ge₁₁.₅As₂₄24Se₆₄.₅ is used for the fabrication of photonic crystal cavities. Quality factors of up to 13000 are demonstrated. The low nonlinear losses have enabled the demonstration of second and third harmonic generation in those cavities with powers up to twice as high as possible in silicon. A computationally efficient model for designing coupled resonator bandpass filters is used to design bandpass filters. Single ring resonators are fabricated using a novel method to define the circular shape of the rings to improve the fabrication quality. The spectral responses of the ring resonators are used to determine the coupling coefficient needed for the design and fabrication of the bandpass filters. A flat top bandpass filter is fabricated and characterized as demonstration of this method. A passive all-optical regenerator is proposed, by integrating a slow-light photonic crystal waveguide with a band-pass filter based on coupled ring resonators. A route of designing the regenerator is proposed by first using the dispersion engineering results for nonlinear pulse propagation and then using the filter responses to calculate the nonlinear transfer function.