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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Ultrasmall silicon quantum dots for the realization of a spin qubit

Perez Barraza, Julia Isabel January 2014 (has links)
No description available.
22

Compact waveguide grating couplers for silicon photonic integrated circuits. / CUHK electronic theses & dissertations collection

January 2010 (has links)
An apodized grating coupler with the best coupling efficiency hitherto reported for shallow-etched waveguide grating couplers is described. By appropriate choice of waveguide/grating thicknesses and varying the coupling strength of the grating coupler via tailoring its fill factor to optimize the mode matching, a coupling loss of only 1.2dB was obtained for each fiber/silicon waveguide interface with a slightly titled optical fiber. / Photonic integrated circuits (PICs) based on Silicon-on-insulator (SOI) substrate were proposed to make miniaturized photonic devices on chip, so that low-cost and compact devices for applications including sensing, inter/intra-chip communications and optical fiber communications could be made. One of the key challenges in the development of highly integrated PICs is efficient coupling of light between a submicron-sized nanophotonic wire and an optical fiber due to the large loss inherent from the mismatch in mode field size between the optical fibers and the nanophotonic wire waveguides. An attractive approach for efficient coupling is to use diffractive grating couplers which show many advantages over alternative approaches. However the angled alignment of the optical fiber to the grating as reported in the previous work is not desirable for a low-cost optical packaging process. / The 2D grating couplers could be used as polarization splitter. Polarization insensitive coupling and polarization-diversity circuits are realized by the 2D grating couplers. We also demonstrated a novel silicon waveguide grating which serves dual functions: as a 1x2 variable integrated beam splitter/combiner and as an out-of plane diffractive element for coupling light. The split ratio can be tuned by changing the launch position of the optical fiber without introducing much excess loss. An integrated Mach-Zehnder interferometer (MZI) is implemented with this novel functional element. This MZI was demonstrated as a demodulator for differential phase-shift-keying (DPSK) signal. / We demonstrated a simple technique to realize vertical fiber coupling with linearly chirped grating periods. No additional fabrication process is required yet a comparable coupling efficiency is achieved with the proposed chirped grating couplers with vertical optical fibers. Design and experimental results of onedimensional (lD) gratings, two-dimensional (2D) gratings, focusing gratings and fully-etched nanoholes gratings are described in the thesis. We also describe the waveguides and grating couplers fabricated on silicon-on-sapphire for mid-infrared applications. / Chen, Xia. / Adviser: H.K. Tsang. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
23

Silicon waveguides and methods to address their polarization sensitivity =: 以硅為基的光波導及其偏振敏度解決方案. / 以硅為基的光波導及其偏振敏度解決方案 / Silicon waveguides and methods to address their polarization sensitivity =: Yi gui wei ji de guang bo dao ji qi pian zhen min du jie jue fang an. / Yi gui wei ji de guang bo dao ji qi pian zhen min du jie jue fang an

January 2003 (has links)
Chan Po Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 79). / Text in English; abstracts in English and Chinese. / Chan Po Shan. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Application of Optical Waveguides --- p.1 / Chapter 1.2 --- Planar Waveguide Characterizations --- p.2 / Chapter 1.3 --- Silicon-On-Insulator Rib Waveguides --- p.3 / Chapter 1.4 --- Polarization compensation schemes --- p.4 / Chapter 1.5 --- Objectives --- p.6 / Chapter 2 --- Silicon-On-Insuiator Rib Waveguides --- p.9 / Chapter 2.1 --- Properties of Silicon Waveguides --- p.9 / Chapter 2.2 --- Single Mode Rib Waveguides Simulations --- p.11 / Chapter 2.3 --- Special design optimisations --- p.14 / Chapter 2.4 --- Fabrications and Results --- p.16 / Chapter 3 --- Polarization Characteristics of SOI Rib Waveguides --- p.20 / Chapter 3.1 --- Properties of silicon and effect of rib structure --- p.20 / Chapter 3.2 --- Polarization affected by Form Birefringence --- p.21 / Chapter 3.3 --- Case Study: Arrayed Waveguide Grating --- p.23 / Chapter 3.4 --- Possibility of polarization Compensation in planar waveguides --- p.26 / Chapter 4 --- Fixed Polarization Compensation Techniques --- p.30 / Chapter 4.1 --- Theoretical analysis of slant rib waveguides on polarization --- p.30 / Chapter 4.2 --- Focused Ion Beam Trimming of SOI waveguides --- p.31 / Chapter 4.3 --- Possible applications --- p.36 / Chapter 5 --- Tuneable Polarization Compensation Techniques --- p.41 / Chapter 5.1 --- stress on rib waveguide for polarization compensation --- p.41 / Chapter 5.2 --- Magnetostriction and Magnetostrictive Materials --- p.42 / Chapter 5.3 --- Sputtering of soft magnetic layer on SOI rib waveguides --- p.46 / Chapter 5.4 --- Test results and Analysis --- p.47 / Chapter 6 --- Advanced SOI Devices --- p.55 / Chapter 6.1 --- Unique planar optoelectronics devices --- p.55 / Chapter 6.2 --- Simulation and Fabrications --- p.57 / Chapter 6.3 --- Test Results and Discussion --- p.58 / Chapter 7 --- Conclusion --- p.62 / Chapter 7.1 --- Summary --- p.62 / Chapter 7.2 --- Future work --- p.63 / Appendices / Chapter A1 --- Effective Index Method --- p.66 / Chapter A2 --- Beam Propagation Method --- p.70 / Chapter A3 --- SOI Rib Waveguide Fabrication --- p.72 / Chapter A4 --- Focused Ion Beam --- p.74 / Chapter A5 --- Polarization Optics --- p.76 / List of Publications --- p.79
24

Piezoelectric energy harvesting devices for low frequency vibration applications

Shen, Dongna, Kim, Dong Joo. January 2009 (has links)
Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Vita. Includes bibliographic references.
25

Study of CMOS active pixel image sensor on SOI/SOS substrate /

Shen, Chao. January 2003 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 67-69). Also available in electronic version. Access restricted to campus users.
26

Fabrication and characterization of hafnium oxide films prepared by direct sputtering /

Zhan, Nian. January 2003 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.
27

SOI CMOS MEMS flow sensors

Haneef, Ibraheem January 2009 (has links)
No description available.
28

The formation of silicon nanoparticles on silicon-on-insulator substrate by thermal annealing

Anyamesem-Mensah, Benedict, January 1900 (has links)
Thesis (M.S.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 69-80. Includes bibliographical references (leaves 81-83).
29

Studies of Si/SiO₂ heterostructures using second harmonic generation

Lu, Xiong. January 2008 (has links)
Thesis (Ph. D. in Physics)--Vanderbilt University, Aug. 2008. / Title from title screen. Includes bibliographical references.
30

Low-voltage radio-frequency CMOS integrated circuits in silicon-on-insulator /

Fong, Neric H. W. January 1900 (has links)
Thesis (Ph. D.)--Carleton University, 2002. / Includes bibliographical references (p. 168-174). Also available in electronic format on the Internet.

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