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Showing papers on "Spatial light modulator published in 1985"


Journal ArticleDOI
TL;DR: It is discovered that the extremely inexpensive Radio Shack liquid-crystal television, with proper modifications, has potential for optical-data-processing applications.
Abstract: The potential of the extremely inexpensive Radio Shack liquid-crystal television (LCTV) as a two-dimensional spatial light modulator has been investigated. The LCTV modulates the transmission of coherent or incoherent light and can either be electronically addressed through a microcomputer or optically addressed with a TV camera. We have measured the transmission characteristics of the device, examined its diffraction pattern, and tested its use as an input device for an optical correlator. We have discovered that, with proper modifications, it has potential for optical-data-processing applications.

183 citations


Journal ArticleDOI
TL;DR: In this article, the structure, operation, fabrication, and performance of a novel, fast response silicon liquid-crystal spatial light modulator for large screen displays and optical data processing are described.
Abstract: Detailed description is given of the structure, operation, fabrication, and performance of the novel, fast‐response silicon liquid‐crystal spatial light modulator. Applications for large screen displays and optical data processing are described.

129 citations


Patent
09 Oct 1985
TL;DR: In this paper, a micromirror spatial light modulator having an associated silicon photodiode for photoaddressing a micro-IR array is presented, and a readout system for providing intensity-to-position encoding and for providing a color image from coded monochromatic input light.
Abstract: A micromirror spatial light modulator having an associated silicon photodiode for photoaddressing a micromirror array, and a readout system for providing intensity-to-position encoding and for providing a color image from coded monochromatic input light.

100 citations


Patent
06 Mar 1985
TL;DR: A spatial light modulator in which the photoreceptor is a capacitively coupled semiconductor in the form of a silicon-silicon dioxide-transparent electrode structure was proposed in this article.
Abstract: A spatial light modulator in which the photoreceptor is a capacitively coupled semiconductor in the form of a silicon-silicon dioxide-transparent electrode structure.

82 citations


Patent
22 Oct 1985
TL;DR: In this paper, a real-time programmable joint transform optical correlator incorporating a magneto-optic spatial light modulator and a liquid crystal light valve was proposed, where cross correlation between the input functions (signals) are obtained through the inverse Fourier transform of the read out coherent illumination and are subsequently output from the correlator.
Abstract: A real-time programmable joint transform optical correlator incorporating a magneto-optic spatial light modulator and a liquid crystal light valve therein. Object functions to be correlated are input into the magneto-optic spatial light modulator by a programmable microcomputer as input signals. Real time correlation takes place at the liquid crystal light valve with a coherent read out beam. Cross correlation between the input functions (signals) are obtained through the inverse Fourier transform of the read out coherent illumination and are subsequently output from the correlator.

53 citations


Journal ArticleDOI
TL;DR: The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve and the details of the control system are given and illustrated with a discussion of timing.
Abstract: The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

31 citations


Journal ArticleDOI
TL;DR: In this article, a high-speed coherent spatial light modulator is proposed based on the coupling of a silicon photodiode and an electrooptic crystal, and the design criteria and theoretical performance are presented.
Abstract: A high-speed, coherent spatial light modulator is under development. It is based on the coupling of a silicon photodiode and electrooptic crystal. The design criteria and theoretical performance are presented. Optical quality of \lambda/20 rms at \lambda = 500 nm over a 1 in aperture has been demonstrated. Submicrosecond write and erase rates are predicted. Heat dissipation limits the predicted continuous rate to 2.5 kHz or higher, depending on required optical quality. Calculated phase MTF is 50 percent at 10 cycles/mm.

29 citations


Book ChapterDOI
TL;DR: In this article, the spatial light modulator, which comprises a photocathode, micro channel plate, mesh electrode, and a LiNbO3 crystal in a vacuum-sealed tube, is described.
Abstract: Publisher Summary This chapter discusses spatial light modulator, which comprises a photocathode, micro channel plate, mesh electrode, and a LiNbO3 crystal in a vacuum-sealed tube. The device is a transducer for incoherent to coherent light conversion; it is highly sensitive and can be used over a wide wavelength range. It can also be used to perform a variety of image processing. When an incoherent input optical image is incident on the photocathode, it creates a photoelectron image. This electric charge image is deposited onto the surface of the electrooptic crystal after electron multiplication by 103 to 104 in the MCP. This electric charge creates a change in the electric field across the crystal. Control of the charge on the surface of the crystal is performed by the use of the secondary electron emission characteristics of the SiO2 layer.

29 citations


Journal ArticleDOI
Dennis R. Pape1
TL;DR: In this paper, a two-dimensional, optically addressed, membrane spatial light modulator is described, which is used to convert incoherent images to coherent images for optical information processing applications.
Abstract: The architecture, operation, and performance of a new two-dimensional, optically addressed, membrane spatial light modulator are described. The modulator, the optical-to-optical deformable mirror device, consists of an array of 128 X128 deformable mirror elements on 25 .im centers integrated on silicon. The device exhibits a sensitivity of 1.7 jJ/cm2 at 525 nm, write times of 25 i. is, and erase times of 40 I.Ls. Images are read out with near-IR illumination. The device can be used to convert incoherent images to coherent images for optical information processing applications.

24 citations


Patent
David L. Hecht1
13 Dec 1985
TL;DR: An optical image bar having a spatial light modulator includes means for decomposing the spatially modulated output radiation of the modulator into a plurality of mutually orthogonal, laterally offset, redundantly modulated, optical field distributions for producing an essentially null-free image as mentioned in this paper.
Abstract: An optical image bar having a spatial light modulator includes means for decomposing the spatially modulated output radiation of the modulator into a plurality of mutually orthogonal, laterally offset, redundantly modulated, optical field distributions for producing an essentially null-free image, without significantly affecting the resolution of the image bar.

22 citations


Journal ArticleDOI
TL;DR: Two electronic manipulation schemes are pro-posed for doubling the resolution of the Scophony scanner, one schemes for analog video signals and one scheme for binary digital video signals, each of which gives superior contrast ratio performance when compared with the flying-spot scanner.
Abstract: An alternative to the conventional flying-spot scanner architecture is the Scophony scanner. The Scophony scanner uses the same optical elements as the more familiar flying-spot scanner: a rotating polygon mirror, an acousto-optic (A/O) modulator, and a laser light source. The flying-spot scanner is designed to construct its image a pixel at a time; no more than one pixel is illuminated at any given instant. The Scophony scanner is designed to image a broad swath of the A/0 modulator's acoustic pulses onto the photoreceptor. Many pixels are illuminated at any given instant in the Scophony scanner. The result is a scanner with a coherent imaging response. This coherent response implies that the phase of the modulator's electronic drive signal for a given pixel profoundly influences the formation of the neighboring pixels at the scanner image plane. This coherent response enables electronic manipulation of the video drive signal to have significant impact on the optical imaging performance of the scanner. In this paper, two electronic manipulation schemes are pro-posed for doubling the resolution of the Scophony scanner, one scheme for analog video signals and one scheme for binary digital video signals. Each scheme gives superior contrast ratio performance when compared with the flying-spot scanner.

Patent
08 Jan 1985
TL;DR: In this paper, a spatial light modulator having a lattice of microgrooves formed on the surface of the silicon photodiode nearest the electro-optic cyrstal was proposed.
Abstract: A spatial light modulator having a lattice of microgrooves formed on the surface of the silicon photodiode nearest the electro-optic cyrstal to prevent lateral charge transfer at this surface.

Patent
23 Dec 1985
TL;DR: An amorphous silicon spatial light modulator that includes a unique three electrode structure that is used to create a two-dimensional electric field distribution in liquid crystal material is described in this paper.
Abstract: An amorphous silicon spatial light modulator that includes a unique three electrode structure that is used to create a two-dimensional electric field distribution in liquid crystal material. This modulator allows for the use of very thin photoconductor layers and a middle electrode in the form of a grating structure to provide control of the field shape while also providing for high spatial resolution.

Journal ArticleDOI
TL;DR: In this paper, a vacuum-demountable prototype electron-beam-addressed spatial light modulator that consists essentially of an electron gun, a microchannel plate, and an electro-optic crystal is investigated.
Abstract: A vacuum-demountable prototype electron-beam-addressed spatial light modulator that consists essentially of an electron gun, a microchannel plate, and an electro-optic crystal is being investigated. This paper discusses the underlying principles of operation of the device, which include the interaction of an electron beam with a microchannel plate and the addressing of an electro-optic crystal with a flux of nonmonoenergetic electrons.

Patent
11 Apr 1985
TL;DR: In this paper, a differentiating spatial light modulator device was proposed, in which a photoreceptor and an electro-optic crystal are isolated by a dielectric mirror, and readout via a polarizing beamsplitter gave an output light related to the spatial gradient of the input light.
Abstract: A differentiating spatial light modulator device in which a photoreceptor and an electro-optic crystal are isolated by a dielectric mirror. The electro-optic crystal is configured to have low or zero longitudinal response, yet is sensitive to transverse electric fields. The fringe field generated by the photoreceptor (photodiode) modultes the crystal birefringence. Readout via a polarizing beamsplitter gives an output light related to the spatial gradient of the input light. In a liquid crystal embodiment of the invention, reversal of the applied voltage gives a driven off state which speeds the erasure. Storage is possible in the smectic liquid crystal phase.

Patent
25 Apr 1985
TL;DR: Improved spatial light modulators, each consisting of an electron beam source formed within a vacuum envelope, a photoelectric layer, and an electro-optical crystal to store electrons emitted from the beam source as a charge to change the optical refraction index thereof, were proposed in this paper.
Abstract: Improved spatial light modulators, each consisting of an electron beam source formed within a vacuum envelope, ie, a photoelectric layer; and a electro-optical crystal to store electrons emitted from the electron beam source as a charge to change the optical refraction index thereof The charge storage surface of the electro-optical crystal constitutes a dielectric multilayer mirror or a specific dielectric film layer whose surface resistance is high and stable enough to store the charge in a high vacuum of 10 -7 torr at an elevated temperature of 350° C

Journal ArticleDOI
TL;DR: In this paper, the construction and operation of a PRIZ spatial light modulator using semi-transparent electrodes and no insulating layers was reported, which is the first report of a non-Soviet built device of this type.

Patent
26 Sep 1985
TL;DR: In this article, an interferometer in Mach-Zehnder configuration comprises beamsplitters and mirrors, which divide an optical beam whose wavefront is to be monitored into an information component and a reference component, and recombine the information and reference components to form an interference pattern that changes dynamically at a spatial light modulator in response to dynamic variations in the atmosphere through which the beam passes.
Abstract: An interferometer in Mach-Zehnder configuration comprises beamsplitters (10, 12) and mirrors (11, 13), which divide an optical beam whose wavefront is to be monitored into an information component and a reference component, and which recombine the information and reference components to form an interference pattern that changes dynamically at a spatial light modulator (14) in response to dynamic variations in the atmosphere through which the beam passes. A spatial light filter (15) comprising a plate with a pin-hole aperture is positioned to transmit the reference component of the beam, but with second-order aberrations being removed from the reference component prior to recombination of the information and reference components. The wavefront of the reference component that recombines with the information component is a substantially unaberrated version of the wavefront of the beam whose wavefront is to be monitored. An acousto-optical beam-steering device (20) steers the reference component in real time so as to maintain substantially continuous alignment of a maximum-intensity centroid of the reference component with respect to the pin-hole aperture of the spatial light filter (15).

Proceedings ArticleDOI
21 May 1985
TL;DR: In this article, the microchannel spatial light modulator (MSLM) in particular is a very promising and versatile, optically addressed device which can intrinsically perform a multitude of operations.
Abstract: Two-dimensional spatial light modulators are expected to be an Integral part of sophisticated optical information, processing or computing systems. The microchannel spatial light modulator (MSLM) in particular is a very promising and versatile, optically addressed device which can intrinsically perform a multitude of operations. Functions which have previously [1,2] been demonstrated on data stored in an MSLM include image thresholding, image addition and subtraction, contrast reversal, contrast enhancement, edge enhancement, and the binary logic operations of NOT, AND, NAND, OR, NOR, XOR, and NXOR.

Patent
23 Dec 1985
TL;DR: In this paper, an optical image bar utilizing polarized light and a coherent spatial light modulator includes birefrigent spatial or angular shearing means for uniformly dividing the spatially modulated radiation of a coherent image bar into a pair of laterally offset, redundantly modulated, orthogonally polarized optical field distributions.
Abstract: An optical image bar utilizing polarized light and a coherent spatial light modulator, includes birefrigent spatial or angular shearing means for uniformly dividing the spatially modulated radiation of a coherent image bar into a pair of laterally offset, redundantly modulated, orthogonally polarized optical field distributions. Imaging optics, which include any spatial filtering and/or polarization filtering elements needed for converting those field distributions into correspondingly modulated spatial intensity distributions, bring the filtered field distributions to focus on an output image plane, thereby producing redundantly modulated, laterally offset, intensity profiles on the output image plane which spatially sum with each other on an intensity basis. The magnitude of the shear is selected so that the image plane offset of those intensity profiles is approximately equal to one half of the nominal image plane pixel pitch of the image bar, whereby each of the intensity profiles redundantly overwrites the interpixel intensity nulls of the other. Spatial shearing is preferred for image bars having telecentric imaging optics, but angular shearing is a practical alternative for some embodiments.

Patent
08 Jan 1985
TL;DR: An electron bombarded silicon spatial light modulator was proposed in this article, in which electrons leaving a microchannel plate amplifier are accelerated to penetrate a silicon photodiode forming electron-hole pairs therein and resulting in significant current gains.
Abstract: An electron bombarded silicon spatial light modulator in which electrons leaving a microchannel plate amplifier are accelerated to penetrate a silicon photodiode forming electron-hole pairs therein and resulting in significant current gains.

Proceedings ArticleDOI
29 Jan 1985
TL;DR: Gustafson as mentioned in this paper proposed a threshold logic element for which analog weighting and thresholding operations are effectively implemented using integrated (or near-integrated) optical technology, such an effective implementation, whichis difficult at best using current all- electronic technology, is important because digitalprocessing systems using threshold logic elements require no more and often many fewer connections and logic levels than do similar systems using conventional logic gates.
Abstract: Electro- optical intensity modulation of near -surface light for opticalsignal processing applicationsSteven C. GustafsonUniversity of Dayton Research Institute300 College Park, Dayton, Ohio 45469AbstractCertain optics -based register -level devices for digital processing applications are con-sidered. These modular devices have electronic binary inputs and outputs and are based onthe electro -optic intensity modulation of near -surface light. The modulation technique com-bines features of a total internal reflection electro- optical spatial light modulator and aLloyd's mirror interferometer. The devices may be described as threshold logic elements forwhich the analog weighting and thresholding operations are effectively implemented usingintegrated (or near -integrated) optical technology. Such an effective implementation, whichis difficult at best using current all- electronic technology, is important because digitalprocessing systems using threshold logic elements require no more and often many fewerinterconnections and logic levels than do similar systems using conventional logic gates.Fewer interconnections and logic levels may in turn provide the foundation for exceptionallyhigh- speed, low- power- consumption, small -size, and otherwise attractive digital processingsystems.IntroductionOptics -based digital processing may be carried out on the processor, register, or gate

15 Nov 1985
TL;DR: In this paper, a flat screen Liquid Crystal Television (LCTV) has been modified and used as a spatial light modulator in a Vander Lugt type coherent optical correlator.
Abstract: : A commercially available flat screen Liquid Crystal Television (LCTV) has been slightly modified and used as a spatial light modulator in a Vander Lugt type coherent optical correlator. The small, (54 mm x 40.5 mm) inexpensive, (approx.= $100) LCTV was used as a replacement for extremely expensive modulators normally used in optical data processing such as the Hughes Liquid Crystal Light Valve and the Litton Magneto-Optic Device. Results show that the resolution, contrast, and speed of the LCTV in its present form, are sufficient for some basic real-time pattern recognition applications. (Author)

Proceedings ArticleDOI
21 Jan 1985
TL;DR: The magneto-optic device responds to the polarized white-light, in which a wide range of color object patterns can be generated, making it very suitable for real-time programmable spatial filter synthesis and object pattern generation for optical signal processings.
Abstract: The application of a programmable magneto-optic spatial light modulator to white-light optical signal processing is presented. We have shown that the magneto-optic device responds to the polarized white-light, in which a wide range of color object patterns can be generated. Since the magneto-optic device is a transmitted type spatial light modulator, it is very suitable for real-time programmable spatial filter synthesis and object pattern generation for optical signal processings. Experimental demonstrations of some of the elementary spatial filter syntheses and pseudocolor encodings are provided.