All-optical logic gates made from GaAs etalons were studied to see if they may be useful for optical computing. We have demonstrated that GaAs etalons may produce a change in output optical signal four times larger than the change in the input signal, and that the contrast of the output signal may be as high as 10 to 1. We have cascaded two GaAs etalons, i.e. the output change in the first causes the second one to switch. We have combined two signal beams and a biasing beam onto a GaAs etalon using polarized beams for a fan-in investigation, and have demonstrated that this setup may be used as an all-optical AND gate. We have also shown that GaAs etalons function well when interfaced to optical fibers by direct butt-coupling. Interconnections between all-optical gates by optical fibers, holographic optical elements, and conventional lenses are discussed.

No description available.

QC 351 A7 no. 85 / A technique is described for suppressing unwanted grain noise in scanned and digitized photographic images. The technique employs the rms granularity statistics of the film to divide, or quantize, the density range of the digital image into distinguishable ranges of density. For Eastman Kodak type 3414 film, the rms granularity statistics determined indicate constant Selwyn granularity for the range of scanning spot diameters from approximately 16 to 4 micrometers, and this result agrees with Kodak data for a 48 micrometer diameter spot. For spots from 16 to 4 micrometers diameter, the rms granularity is also determined to be a function of the square root of diffuse density. The number of distinguishable density levels, required to sup- press the grain noise of the digitally processed image, is found to be directly related to the scanning spot diameter. Finally, evaluation of the resulting digitally processed images indicates that subjective image quality is directly related to the spatial resolution of the image. That is, with the grain noise suppressed, subjective quality is improved by scanning the original image with a smaller diameter spot.

Typescript, etc. / Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Cheng, Lap Kei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.I / 摘要 --- p.II / ACKNOWLEDGEMENTS --- p.V / TABLE OF CONTENTS --- p.IV / INTRODUCTION --- p.0 / Chapter 1.1 --- Different ways to achieve all-optical tunable delay --- p.2 / Chapter 1.1.1 --- Optical buffer realized with optical switching --- p.2 / Chapter 1.1.2 --- Slow light technique --- p.3 / Chapter (i) --- Basics of slow light --- p.4 / Chapter (ii) --- Slow light via electromagnetically induced transparency (EIT) --- p.6 / Chapter (iii) --- Slow light via coherent population oscillation (CPO) --- p.7 / Chapter (iv) --- Slow light via optical parametric amplification (OPA) --- p.8 / Chapter (v) --- Slow light via stimulated Raman and Brillouin scattering --- p.8 / Chapter 1.1.3 --- Tunable delay using wavelength conversion together with chromatic dispersion --- p.10 / Chapter 1.1.4 --- Comparison of different schemes for constructing all-optical delay line --- p.11 / Chapter 1.2 --- Overview of the thesis --- p.12 / References --- p.14 / ALL-OPTICAL SWITCHING OF DPSK SIGNAL IN AN SOA USING NONLINEAR POLARIZATION ROTATION --- p.18 / Chapter 2.1 --- Introduction --- p.19 / Chapter 2.2 --- Birefringence and nonlinear polarization rotation --- p.20 / Chapter 2.3 --- Differential-phase-shift keying (DPSK) modulation format --- p.22 / Chapter 2.4 --- Experimental setup --- p.23 / Chapter 2.5 --- Experimental results --- p.25 / Chapter 2.6 --- Conclusion --- p.29 / References --- p.30 / WIDEBAND SLOW LIGHT VIA STIMULATED BRILLOUIN SCATTERING IN AN OPTICAL FIBER USING A PHASE-MODULATED PUMP --- p.32 / Chapter 3.1 --- Introduction --- p.33 / Chapter 3.2 --- Stimulated Brillouin scattering (SBS) --- p.34 / Chapter 3.3 --- Slow light via SBS --- p.35 / Chapter 3.4 --- Experimental setup --- p.37 / Chapter 3.5 --- Experimental result --- p.39 / Conclusion --- p.42 / References --- p.43 / SIGNAL WAVELENGTH TRANSPARENT SBS SLOW LIGHT USING XGM BASED WAVELENGTH CONVERTER AND BRILLOUIN FIBER LASER --- p.45 / Chapter 4.1 --- Introduction --- p.46 / Chapter 4.2 --- Brillouin fiber laser and XGM wavelength converter --- p.47 / Chapter 4.3 --- Operating principle --- p.50 / Chapter 4.4 --- Experimental setup and results --- p.51 / Conclusion --- p.56 / References --- p.57 / ALL-OPTICAL TUNABLE DELAY LINE FOR CHANNEL SELECTION IN A 40-GB/S OPTICAL TIME DIVISION MULTIPLEXING SYSTEM --- p.59 / Chapter 5.1 --- Introduction --- p.60 / Chapter 5.2 --- Principle of four-wave mixing --- p.61 / Chapter 5.3 --- Channel selection in an OTDM system --- p.63 / Chapter 5.4 --- Experimental setup --- p.64 / Chapter 5.5 --- Experimental results --- p.67 / Conclusion --- p.70 / References --- p.71 / TUNABLE OPTICAL DELAY WITH CSRZ-OOK TO RZ-OOK OPTICAL DATA FORMAT CONVERSION USING FOUR-WAVE MIXING WAVELENGTH CONVERSION AND GROUP VELOCITY DISPERSION --- p.73 / Chapter 6.1 --- Introduction --- p.74 / Chapter 6.2 --- Carrier-Suppressed Return-to-Zero --- p.76 / Chapter 6.3 --- Operating Principle --- p.77 / Chapter 6.4 --- Experimental setup --- p.79 / Chapter 6.5 --- Experimental result --- p.81 / Conclusion --- p.86 / References --- p.87 / CONCLUSION --- p.90 / Chapter 7.1 --- Summary of work --- p.90 / Chapter 7.2 --- Prospects of future work --- p.92 / APPENDIX: LIST OF PUBLICATIONS A

Zhang, Qian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 97-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

No description available.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on December 21, 2009. Thesis advisor: Dr. Kannappan Palaniappan. Includes bibliographical references.

Thesis (M.S. in M.E.)--School of Mechanical Engineering, Georgia Institute of Technology, 2004. Directed by Thomas R. Kurfess. / Includes bibliographical references (leaves 110-112).