The optical ring cavity has been studied for about ten years, both theoretically and experimentally. In these studies the uniform plane wave approximation has been used. In this work we investigate effects which result from the retention of the transverse diffraction. We establish that transverse structure is inevitable since plane wave fixed points are susceptible to transverse instabilities (modulational instability). We show that this instability is a universal mechanism for initiating various interesting and complicated, yet understandable, dynamical responses in a one and a two transverse dimensional cavity.

Lai, Wai Chiu King. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 87-89). / Abstracts in English and Chinese. / LIST OF TABLES --- p.vi / LIST OF FIGURES --- p.vii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Organization of the thesis --- p.3 / Chapter 2. --- Literature Survey --- p.5 / Chapter 2.1 --- Micro Hinges --- p.5 / Chapter 2.2 --- Assembly --- p.5 / Chapter 2.2.1 --- Manual Lift Up Process --- p.5 / Chapter 2.2.2 --- Assembly by On-substrate Actuators --- p.6 / Chapter 2.2.3 --- Assembly by Surface Tension Force --- p.8 / Chapter 2.2.4 --- Assembly by Thermal Shrinkage --- p.8 / Chapter 2.2.5 --- Assembly by Ultrasonic Triboelectricity --- p.9 / Chapter 2.3 --- Summary of Literature Survey --- p.9 / Chapter 3. --- Design & Analysis --- p.11 / Chapter 3.1 --- Micro-Assembly by Centrifugal Force --- p.11 / Chapter 3.2 --- Micro Mass Platform --- p.12 / Chapter 3.2.1 --- Micro Mirror --- p.12 / Chapter 3.2.2 --- Rotation Sensor --- p.15 / Chapter 3.3 --- Fabrication of Micro Structures --- p.16 / Chapter 3.4 --- Force Analysis --- p.18 / Chapter 3.4.1 --- Centrifugal Force --- p.18 / Chapter 3.4.2 --- Van der Waals Forces --- p.20 / Chapter 3.4.3 --- Capillary Force - (1st model) --- p.22 / Chapter 3.4.4 --- Capillary Force - (2nd model) --- p.23 / Chapter 3.4.5 --- Casimir Force --- p.26 / Chapter 3.4.6 --- Spring force of the beam --- p.27 / Chapter 3.4.7 --- Comparison of Forces --- p.28 / Chapter 3.4.8 --- Stress on Polysilicon --- p.30 / Chapter 4. --- Surface Force Measurement --- p.32 / Chapter 4.1 --- Experimental Setup --- p.33 / Chapter 4.2 --- Experimental Result --- p.34 / Chapter 4.2.1 --- Control Experiment of Rotation Sensor --- p.34 / Chapter 4.2.2 --- Freed-state and Snap-down-state --- p.35 / Chapter 4.2.3 --- Summary of the Experimental Data --- p.36 / Chapter 4.3 --- Comparison between Modelled Results and Experimental Data --- p.42 / Chapter 5. --- Assembly Experiment --- p.45 / Chapter 5.1 --- Experimental Setup --- p.45 / Chapter 5.2 --- Experimental Results --- p.46 / Chapter 5.3 --- Comparison among different chips --- p.52 / Chapter 6. --- Assembly Experiment (Double Chips) --- p.57 / Chapter 6.1 --- Experimental Setup --- p.57 / Chapter 6.2 --- Experimental Results --- p.58 / Chapter 6.2.1 --- Surface Profile measurement --- p.58 / Chapter 6.2.2 --- Summary of the surface profile measurement --- p.68 / Chapter 6.2.3 --- Assembly Results --- p.69 / Chapter 7. --- Assembly Experiment (Monitoring System in MUMPs46) --- p.72 / Chapter 7.1 --- Experimental Setup --- p.72 / Chapter 7.2 --- Experimental Results --- p.74 / Chapter 8. --- Other tested micro structures --- p.80 / Chapter 9. --- Conclusion --- p.82 / Chapter 10. --- Future Work --- p.83 / Chapter A. --- Appendix --- p.84 / Bibliography --- p.87

No description available.

Chow Kin Kee. / May, 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

In this work, the author aims to trace some of the transformative effects of televisual technologies in contemporary post-industrial culture, and to critically assess their impact on the way knowledge is produced, and experience a sense of embodiment and social agency. The relation between humans and tools is questioned, and the hybridity of words such as technoculture and biotechnology is investigated, arguing that the separation of human and technology,and body and tool, at the level of both existence and knowledge is a synthetic distinction. Specifically, the author concentrates on some of the medium specific effects of postclassical visualising technologies, from high-end ensembles such as virtual reality and medical imaging apparatuses, to the mundane apparatus of television and the remote control device. Such ways of seeing, it is argued, collaborate in producing an emergent tele-body, or a telesomatic mode of perception and knowing which exceeds standard epistemologies of vision in both science and the everyday. This work thus aims to develop a theoretical and conceptual framework for understanding the variable effects of postclassical technovision and televisuality upon our modes of embodiment. / Doctor of Philosophy (PhD)

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: P.E. Jessop Includes bibliographical references ( leaves 166-179).

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Room temperature vertical cavity lasing at the wavelength of 433nm has been successfully realized in InxGa₁₋xN/InyGa₁₋yN multiple quantum well without Bragg mirrors under photo-excitation. At high excitation intensity, one of the modes of the Fabry-Perot cavity formed by the GaN/sapphire and the GaN/air interfaces, shows a strong superlinear increase in intensity with excitation intensity rise. The vertical cavity surface emitting laser (VCSELs) structure is grown by metal-organic chemical vapor phase deposition and the threshold is as low as 200kW/cm². The lasing in the sample probably results from the ultrahigh material gain due to the spontaneous formation of dense array of nanoscale InGaN quantum dots (QDs) having an exceptional high area density. / Singapore-MIT Alliance (SMA)

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007) Vita. Includes bibliographical references.

One of the key advances in photonic technology in recent decades was the development of a new type of diode lasers emitting in the visible and infrared region. These vertical cavity surface-emitting lasers (VCSELs) emerged from a laboratory curiosity in 1977 [13] to an object of industrial mass production [14] and are currently used in many applications. The applications include communication, printing, and absorption spectroscopy [15]. Their rise in credibility has largely been motivated by the rapid evolution of their performance, the more sweeping recognition of their compatibility with low-cost wafer-scale fabrication, and their possible formation into specific arrays with no change in the fabrication procedure. Various applications such as advanced chemical sensors and high-density optical storage require coherent and small-size ultraviolet-emitting devices (below 400nm). Therefore, to extend the VCSEL emission to the ultraviolet (UV) region, intensive efforts have been made in the VCSEL technology. However, the achievement of such UV VCSEL is very challenging because of the various limitations and issues. The issues noticeably include the carrier injection, optical confinement, and highly reflective distributed Bragg reflectors (DBR) structures with a broad bandwidth operating in the UV region [16]. In this context, motivated by the reported large refractive index induced by boron incorporation [7], we propose to introduce the boron-based material systems (BAlGaN) as an innovative solution to address some of the encountered difficulties. The objective of the proposed research is to investigate and optimize new wide-bandgap BAlGaN material systems and illustrate their incorporation into the building blocks of vertical cavity surface-emitting laser structures for operation in the UV spectral range (<400nm). Toward this goal, we have focused our research activities in three main directions. The first direction is devoted to the simulation of DBRs reflectivity by taking into consideration the experimental refractive indexes. Once the materials needed in the different components of the VCSEL are well defined, the second direction lies in the achievement of growth conditions optimization and characterization of the new wide-bandgap BAlGaN material systems. The study has led to the structural and morphological quality improvement of (B,Al,Ga)N materials. Unique optical properties of the BGaN and BAlN materials were also demonstrated. Upon demonstrating the materials' promising optical characteristics, the final direction consists of the epitaxial growth and characterization of the highly reflective DBRs and active region of the UV VCSEL structure.