Showing papers on "Spatial light modulator published in 1980"
Patent•
29 Sep 1980
TL;DR: In this article, a hologram is produced by illuminating an object via a coherent light source and associated optics, or by digital components or photographic components, imaged onto, for example, a television camera to selectively provide either a real time, or a non-real time, system.
Abstract: A hologram, produced by illuminating an object via a coherent light source and associated optics, or by digital components or photographic components, is imaged onto, for example, a television camera to selectively provide either a real time, or a non-real time, system When written directly onto the camera, the hologram is used in a real time system, whereas the digital or film input to the camera provides the combination for a non-real time system The image is converted into a corresponding electrical video signal via the camera, and the signal is supplied to a selected spatial light modulator Subsequent illumination by a read coherent light source reconstructs the hologram into a three-dimensional image of the original subject matter, which then may be viewed via a selected optics system
37 citations
TL;DR: A 100-bit slitlike aperture array spatial light modulator has been developed using 8.8/65/35 PLZT for a high-bit-density 1-D hologram memory and the most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized.
Abstract: A 100-bit slitlike aperture array spatial light modulator has been developed using 88/65/35 PLZT for a high-bit-density 1-D hologram memory The most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized The lowest SNR was 86, and rise time and fall time have been 30 μsec and 8 μsec, respectively, at 190-V halfwave voltage One-dimensional holographic storage experiments have been successfully performed using this PLZT spatial light modulator
18 citations
TL;DR: In this article, an array of independent picture elements on a spatial light modulator (SLM) is presented, in which each element is in one of two stable equilibrium states, and their stability as well as the means for switching between them are exhibited theoretically and experimentally.
Abstract: For an array of independent picture elements on a spatial light modulator (SLM), we present a configuration where each element is in one of two stable equilibrium states. Their stability as well as the means for switching between them is exhibited theoretically and experimentally. The distinguishing feature of the array of the independent bistable switching elements is that the implementation of each involves only a single active element in the feedback loop so that optimum use of the active area of the SLM is made.
16 citations
Patent•
05 Nov 1980
TL;DR: In this paper, an electric potential is applied to the crystal either transversely to the direction of the light or in line with the direction according to either the Kerr effect or the Pockels effect.
Abstract: Coherent light such as a laser beam is spatially modulated by causing it to interact at a photosensitive material such as a crystal with a focussed image of non-coherent light An electric potential is applied to the crystal either transversely to the direction of the light or in line with the direction of the light according to either the Kerr effect or the Pockels effect Typical crystals include Bismuth-silicon-oxide and strontium-barium-niobate
14 citations
22 Aug 1980
TL;DR: The NODP as mentioned in this paper combines the residue arithmetic representation with a spatial light modulator operating as an optically controlled birefringence mirror, capable of performing addition, subtraction, multiplication and division.
Abstract: This paper deals with an optical arithmetic unit called Numerical Optical Data Processor (NODP), capable of performing addition, subtraction, multiplication and division. The NODP combines the residue arithmetic representation with a spatial light modulator operating as an optically controlled birefringence mirror. The quantity of interest is the relative phase delay between polarization components of light along the fast and slow axes of the controlled birefringence mirror. This phase delay is addititive during several reflections (the basic addition operation) and is detected in terms of the intensity outputting through an analyzer. In the past we have been troubled by slow response times of the LCLV. That has been solved by chopping the input light between two levels. Several addition operations have been performed and results look encouraging. In this paper the operation of the device and some parts of the theory will be discussed and data showing addition will be presented!© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
12 citations
25 Apr 1980
TL;DR: The Microchannel Spatial Light Modulator (MSLM) is a relatively new, highly sensitive, optically-addressed light modulator that is being developed for low-level light, real-time, optical information processing as discussed by the authors.
Abstract: The Microchannel Spatial Light Modulator (MSLM) is a relatively new, highly sensitive, optically-addressed light modulator that is being developed for low-level-light, real-time, optical information processing. This Paper presents an update of recent progress on the development of the MSLM. Vacuum-sealed and demountable devices employing electro-optic crystals of LiTaO3 and LiNbO3 respectively, are evaluated. These devices are found to have similar characteristics. A halfwave exposure sensitivity of 8.4 nJ/cm2 and a long-term optical information storage time of more than two weeks have been demonstrated with the vacuum-sealed LiTaO3 device; the demountable LiNbO3 MSLM has been cycled at 10 frames per second.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
12 citations
TL;DR: In this article, a passive real-time spatial light modulator (SLM) using an oil layer as phase modulator of a radiation field is described, and experiments with a SLM as incoherent to coherent image transformer are performed, revealing the limits in resolution and response speed.
8 citations
25 Apr 1980
TL;DR: In this paper, the spatial frequency response of an electrooptic spatial light modulator is calculated for both analytic (exponential hole/gaussian electron) and iterative (exposure-induced charge transport) continuous charge distributions.
Abstract: The theoretical resolution of an electrooptic spatial light modulator [such as the Pockels Readout Optical Modulator (PROM)] is a function of the electrostatic field distribution arising from stored point charges located within the active electrooptic crystal layer. The Fourier transform of the voltage distribution (which can be directly related to the modulation transfer function) is expressed as a function of the charge location within the electrooptic crystal. In addition, the resultant analytic expression contains the dielectric constants of the blocking layers and electrooptic crystal, and the thicknesses of the three layers. This formulation allows the effects of charge trapping within the bulk of the electrooptic crystal to be modeled. In particular, the low spatial frequency response decreases linearly and the high spatial frequency response decreases exponentially with the distance of the point charge from the dielectric blocking layer/electrooptic crystal interface. Thus the overall sensitivity and resolution are degraded strongly by charge storage in the bulk away from the interface. Utilizing superposition, this formulation can be readily extended to accommodate arbitrary charge distributions arising from different exposure parameters. The spatial frequency response of the PROM is calculated for both analytic (exponential hole/gaussian electron) and iterative (exposure-induced charge transport) continuous charge distributions. The limiting form of the high spatial frequency response is shown to be independent of the particular distribution of volume charge. The implications of these results for device design and operation are discussed.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
6 citations
30 Jan 1980
TL;DR: New real-time image processing, optical pattern recognition, and optical signal processing applications of this SLM are described with emphasis on the accuracy of the photo-DKDP based real- time experiments.
Abstract: The photo-DKDP spatial light modulator is found to be an excellent candidate real-time and reusable 2-D optically-addressed spatial light modulator. Extensive sensitometry, MTF, and other device data are reported with emphasis on a new field dependent photo-sensitivity and the importance of linear MTF data. A new spatial birefringent modulation transfer function is described and its use in obtaining more linear device response, bias level suppression, phase modulation and 1 msec erase time are noted. New real-time image processing, optical pattern recognition, and optical signal processing applications of this SLM are described with emphasis on the accuracy of the photo-DKDP based real-time experiments.
5 citations
30 Jan 1980
TL;DR: In this paper, the Fourier transform of the voltage distribution is derived as a function of the charge location within the electrooptic crystal, and the resultant analytic expression contains the dielectric constants of the blocking layers and electro optic crystal and the thicknesses of the three layers.
Abstract: The theoretical resolution of an electrooptic spatial light modulator [such as the Pockels Readout Optical Modulator (PROM)] is a function of the electrostatic field distribution arising from stored point charges located within the active electrooptic crystal layer. The Fourier transform of the voltage distribution (which can be directly related to the modulation transfer function) is derived as a function of the charge location within the electrooptic crystal. In addition, the resultant analytic expression contains the dielectric constants of the blocking layers and electrooptic crystal, and the thicknesses of the three layers. This formulation allows the effects of charge trapping within the bulk of the electrooptic crystal to be modeled. In particular, the low spatial frequency response decreases linearly and the high spatial frequency response decreases exponentially with the distance of the point charge from the dielectric blocking layer/electrooptic crystal interface. Thus the overall sensitivity and resolution are degraded strongly by charge storage in the bulk away from the interface. Utilizing superposition, this formulation can be readily extended to accommodate arbitrary charge distributions arising from different exposure parameters. The implications of these results for device design and operation are discussed.
3 citations
01 Jan 1980
TL;DR: The Microchannel Spatial Light Modulator is a versatile, optically-addressed, highly -sensitive device that is well suited for low-light-level, real-time, optical information processing.
Abstract: The Microchannel Spatial Light Modulator (MSLM) is a versatile, optically-addressed, highly -sensitive device that is well suited for low-light-level, real-time, optical information processing. It consists of a photocathode, a microchannel plate (MCP), a planar acceleration grid, and an electro-optic plate in proximity focus. A framing rate of 20 Hz with full modulation depth, and 100 Hz with 20% modulation depth has been achieved in a vacuum-demountable LiTaO3 device. A halfwave exposure sensitivity of 2.2 nJ/cm2 and an optical information storage time of more than 2 months have been achieved in a similar gridless LiTaO3 device employing a visible photocathode. Image processing operations such as analog and digital thresholding, real-time image hard clipping, contrast reversal, contrast enhancement, image addition and subtraction, and binary level logic operations such as AND, OR, XOR, and NOR can be achieved with this device. This collection of achievable image processing characteristics makes the MSLM potentially useful for a number of smart sensor applications.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
19 Nov 1980
TL;DR: In this article, the combination of a high resolution video system working with a spatial light modulator results in a system in which holograms can be produced and converted to electrical signals for the purpose of transmission to remote locations.
Abstract: The combination of a high resolution video system working with a spatial light modulator results in a system in which holograms can be produced and converted to electrical signals for the purpose of transmission to remote locations. The hologram is converted to an optical signal where the original image is reconstructed. This paper describes the proposed technique and shows some results from a laboratory experiment. The experimental results were obtained using a "General Electric Coherent. Light Valve" as the input transducer to the optical system.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
30 Jan 1980
TL;DR: In this article, the photo-addressed thermoplastic device as an optical spatial light modulator in terms of gray scale and MTF is reported, with the use of a spatial carrier.
Abstract: Characterization results of the photo-addressed thermoplastic device as an optical spatial light modulator in terms of gray scale and MTF are reported in this paper. Image recording is carried out with the use of a spatial carrier. Measured results indicate MTF response well in excess of 200l/mm.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
27 May 1980
TL;DR: A passive real time spatial light modulator, using an oil layer as phase modulator of a radiation field, is described, revealing the limits in resolution and response speed.
Abstract: A passive real time spatial light modulator (SLM), using an oil layer as phase modulator of a radiation field, is described. Experiments with a SLM as incoherent to coherent image transformer were performed, revealing the limits in resolution and response speed.
29 Feb 1980
TL;DR: The coherent light valve (CLV) as mentioned in this paper is a video-input spatial light modulator developed for real-time optical processing that modulates the optical aperture by modulating a raster-scanned electron beam.
Abstract: The coherent light valve is a video-input spatial light modulator developed for real-time optical processing. It was developed as a modified form of the commercial GE light valve TV projection system. The video input signal phase modulates the optical aperture by modulating a raster-scanned electron beam. At compatible TV rates (525/30) the CLV system has a bandwidth of 10-15 MHz and a dynamic range of 40 dB or more . Higher scan rates have demonstrated bandwidths up to 100 MHz, and a special CLV tube design can operate above 100 MHz. Recently compact rack-mounted processor configurations, suitable for user environments, have been developed. This paper reviews past and present work and offers some predictions regarding future developments of the CLV system.