• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 85
  • 24
  • 10
  • 8
  • 8
  • 8
  • 8
  • 8
  • 8
  • 2
  • Tagged with
  • 133
  • 133
  • 133
  • 33
  • 27
  • 19
  • 18
  • 16
  • 15
  • 15
  • 13
  • 13
  • 12
  • 10
  • 9
  • 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

Optical signal processing and real world applications /

Naulleau, Patrick. January 1993 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 1993. / Typescript. Includes bibliographical references (leaves 147-148).
22

Optical signal processing Poisson image restoration and shearing interferometry /

Hong, Yie-Ming, January 1973 (has links)
Thesis (Ph. D.)--University of California, San Diego, 1973. / Vita. Includes bibliographical references (leaves 236-242).
23

Synthesis of low k1 projection lithography utilizing interferometry /

Cropanese, Frank C. January 2005 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 2005. / Typescript. Includes bibliographical references (p. 81-82).
24

A direct temporal domain approach for ultrafast optical signal processing and its implementation using planar lightwave circuits /

Xia, Bing, 1972 Nov. 7- January 2006 (has links)
No description available.
25

A user oriented language for image acquisition, manipulation, storage and display on the McScan system.

Frazer, Robert Alan. January 1971 (has links)
No description available.
26

Single and multiple level structures in texture description

Gupta, Kamal Kant, 1957- January 1981 (has links)
No description available.
27

Evaluation of a Binary Spatial Light Modulator Correlator Using Time-Domain Polarity Coincidence Correlation Theory

Posluszny, Thomas J. 01 January 1985 (has links) (PDF)
Time-domain Polarity Coincidence Correlators (PCC) have been studied for the possible extension of these theories to the spatial-domain in the context of an optical PCC. The existing body of knowledge has been found to be inadequate for direct application to the spatial-domain. However, by remodeling the type of clipper or hardlimiter used in the development of the existing theory from a signum (bipolar) clipper to a binary (unipolar) clipper, a new expression for the output signal-to-noise ratio of an optical PCC is developed. This modification is necessary to account for the unipolar nature of light intensity. Both the existing time-domain and new spatial-domain PCC expressions are valid for the case of additive narrowband (bandwidth much less than the signal frequency) Gaussian-distributed noise at the inputs of the correlator. An optical experiment was constructed to evaluate a new type of binary spatial light modulator, the Litton Data Systems 128 x 128 Magneto-Optic Array. To accomplish this, a noiseless single frequency (fc) sinusoidal one-dimensional reference was correlated with a sinusoidal signal of equal frequency and phase to which gaussian-distributed noise was added. Both signals were hardlimited prior to correlation. Noise sources having bandwidths of 0.1 fc and0.5 fc were investigated to test the robustness of the narrowband constraints. The input data sets had signal-to-noise ratios of -10.0dB and -20.0dB. For both of these conditions the experimental data was found to be in excellent agreement with the new expression for the narrowband case. In the wideband case, the results were significantly different from the new expression, thereby corroborating the necessity of meeting the narrowband constraint. Both the time-domain and spatial-domain expressions are highly-dependent on the output filtering (after hardlimiting and multiplication) characteristics. The effect of filter insertion loss, at the signal frequency (fc), for the unipolar or optical case was examined as part of this research. It was found that the output signal-to-noise ratio increases as the carrier frequency components are attenuated. This affect, which is a direct result of the multiplication of the reference with the input signal within the PCC, is greater for input signal-to-noise ratios above -10dB. For input signal-to-noise ratios below -10dB the output signal-to-noise ratio asymptotically approaches a constant. This output signal-to-noise independence on input signal-to-noise is due to the combined effect limiting signal (which is mostly noise) amplitude information by the hardlimiter and the bounding of the spatial correlation by the low pass filter.
28

Parametric wavelength exchange and its application in high speed optical signal processing

Shen, Mengzhe., 沈梦哲. January 2009 (has links)
published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
29

Nonlinear etalons and nonlinear waveguides as decision-making elements in photonic switching.

Jin, Ruxiang. January 1989 (has links)
This dissertation describes our recent results in the study of various types of photonic switches. Special attention is given to the devices with Fabry-Perot etalon or planar waveguide structures based on dispersive optical nonlinearities. Basic optical logic functions, such as digital pattern recognition, symbolic substitution, and all-optical compare-and-exchange operation are demonstrated using ZnS and ZnSe nonlinear interference filters. Differential gain, cascading, and optical latching circuits are demonstrated using GaAs/AlGaAs multiple-quantum-well nonlinear etalons that are compatible with diode-laser sources, and the relationship between differential gain and device response time is established through a thorough investigation of the switching dynamics. Preliminary results also indicate that optical fibers can be used as interconnects between optical logic gates. Picosecond all-optical switching with good (> 3:1) contrast is demonstrated for the first time in single-mode strip-loaded GaAs/AlGaAs nonlinear directional couplers (NLDC's). The anisotropy of quantum-well structure to light polarization is used to achieve polarization-dependent two-beam switching, and the optical Stark effect is used to demonstrate all-optical modulation in an NLDC with subpicosecond recovery time.
30

Demonstration of capabilities of gallium arsenide etalons for practical optical logic

Hanson, Craig Demorest, 1956- January 1989 (has links)
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.

Page generated in 0.154 seconds