Abstract: The present invention provides an optical device according to this invention comprising a light transmitting optical member of a high molecular material containing mobile ions, and a pair of electrodes formed on surfaces of the optical member, a required potential difference being provided between the electrodes so as to cause ion conduction in the optical member and to reversibly vary a refractive index of the optical member. According to this invention, a refractive index is reversibly varied due to ion conduction, whereby the modulation of a transmitted beam or a reflected beam by the optical device can be reversibly controlled.

Abstract: The present invention relates to a novel spatial light modulator comprising a plurality of individual pixels that each contain separate detectors, electronic circuitry, and optical modulators. A primary application of such a spatial light modulator is to provide the requisite nonlinear relationship between a plurality of optical beams fanned in to each detector on the one hand, and a plurality of optical beams fanned out from such modulator on the other, on a pixel-by-pixel basis. In one embodiment, the spatial light modulator is configured to differentially amplify the inputs to two separate detectors within each pixel, and to transform iORIGIN OF INVENTIONThe U.S. Government has certain rights in this invention pursuant to Contract No. F49620-87-C0007, awarded by the Department of the Air Force, and to Grant No. AFOSR-89-0466, awarded by the Defense Advanced Research Projects Agency through the Department of the Air Force.

Abstract: A technique for reducing interpixel crosstalk in an electrooptic total internal reflection light modulator image bar. A particular electrode length is selected to tailor a portion of the spatial frequency response of the image bar. The pixel size and quality resulting from a voltage difference between electrodes are determined primarily by the overall image bar spatial frequency response, and a set of preferred physical parameters can be determined by selecting parameter values to provide the desired spatial frequency response. It has been found that a desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less than about 1/P, where f is the spatial frequency and P is the minimum pixel pitch. Further, it has been found that a particular electrode length provides the desired response for small absolute values of f. The particular electrode length is approximately E.sup.1/2 P/.gamma.

Abstract: A photodiode array composed of sharply tuned at consecutively different wavelengths are disclosed with the vertical resonance cavity. Semiconductor superlattice distributed Bragg reflectors can be used as the resonance cavity to achieve sharp tuning and monolithic integration, and the wedged distributed Bragg reflector configuration resonance cavity provides a sequential wavelength detection range. A linear array having resolution a fraction of the photodiodes bandwidth and a square-matrix array with a wedged etalon for high resolution, are disclosed. The disclosed photodiode array make a pocket-type wavelength meter feasible and can be used as a substitute for a spectrometer.

Abstract: A technique for reducing interpixel crosstalk by selecting particular illumination conditions and thus tailoring a portion of the spatial frequency response of an optical image bar. A desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less than about 1/P, where f is the spatial frequency and P is the minimum pixel pitch. A skew angle of zero and a grazing angle that is approximately twice the interorder diffraction angle provides the desired cutoff of the response for absolute values of f above about 1/P. The desired frequency response for absolute values of f near zero can be achieved by selecting appropriate values for other physical parameters.

Abstract: A device for modulating light, wherein a layer of material having a superconducting state is placed in the optical path of a light source and is switched between transparent, non-superconducting and non-transparent, superconducting states by a modulation circuit, thereby providing optical data modulation. A cooling device is provided to maintain the layer of material in its superconducting state. The light source is maintained at a constant optical output which reduces spectral dispersion.

Abstract: The electrooptic internal reflection modulator of the present invention provides a technique for reducing interpixel crosstalk by using a compensation filter to help define the spatial frequency response of an image bar. The diffraction efficiency of the system is in part defined by a set of properties of the modulator, the illumination and the imaging subsystems, and is characterized by a spatial frequency response. It has been found that a desirable frequency response is one that approximates sin(.pi.Pf) for absolute values of f less then 1/P, where f is the spatial frequency and P is the minimum pixel pitch.

Abstract: Increasing the addressing capability of an optical image bar having a particular pixel center-to-center spacing (pixel pitch) is accomplished by employing a plurality of N electrodes per pixel. Compared to an optical image bar with one electrode per pixel, this provides N times as many locations for the electric potential transition which establishes the center of the pixel. The provision of multiple electrodes per pixel interval can be used to implement interlacing.

Abstract: A spatial light modulator includes an electro-optic crystal plate and a mesh electrode for capturing secondary electrons emitted from the crystal plate. Primary electrons carrying an image corresponding to an input optical image are incident on the front surface of the crystal plate to write a charge pattern thereon. In a writing operation, a dc voltage and a ramp voltage is applied to the mesh electrode and the back surface of the crystal plate, respectively. The dc voltage and a variation range of the ramp voltage are shifted to obtain a desired input/output characteristic of the device. Alternatively, a decreasing rate of the ramp voltage is changed to obtain a desired characteristic.

Abstract: Method and apparatus for electro-optically modulating the intensity of an incident light beam including a coupling prism with a high reflective index, a semiconductor substrate in optical contact with the coupling prism and having a conductive area formed therein, an organic electro-optic film formed on the substrate and covering at least a portion of the conductive area, and a transmission line disposed above the electro-optic film and cooperating with the conductive area to form electrodes for use in applying an electric field across the electro-optic film. Light directed through the substrate by the coupling prism couples with surface plasmons at the film-to-metal interface and is selectively reflected or absorbed depending upon whether or not an electric field is applied.

Abstract: The TIR modulator has an electrode array distributed across an area of the reflecting surface of the electro-optic material. The electrode array has interdigitated electrodes extending inward from a rectangular-shaped outer electrode conducting block and outward from a diamond-shaped inner electrode conducting block. A diamond-shaped area with no electrodes is preferably symmetrically within the inner electrode conducting block of the electrode array on the reflecting surface. The uniform voltage difference between the electrodes and the varying lengths of the electrodes creates a fringe electrical field in the electro-optical material and an optical phase grating to diffract the incident light on the reflecting surface. The zero order nondiffracted light becomes the output beam. The optical phase grating will control the incident beam's optical profile at the modulator (near field) and hence the imaged spot size at a focus at the image plane (far field).

Abstract: A photorefractive system is disclosed containing interposed between electrodes an electrophotographic photoreceptor layer unit and a layer having a second order polarization susceptibility of greater than 10.sup.-9 electrostatic units comprised of organic polar aligned noncentrosymmetric molecular dipoles having an electron donor moiety linked through a conjugated .pi. bonding system to an electron acceptor moiety. The device can be employed to transfer information from one source of electromagnetic radiation to another.