Abstract: A dynamic multiple-wavelength filter which selects at least one wavelength from a beam of radiation incident on a Stratified volume Holographic Optical Element (SVHOE) in accordance with the Bragg condition. The SVHOE has a number n of grating layers i and a hologram of a grating vector K.sup.i is recorded in each grating layer i. A number n-1 of buffer layers are interposed between grating layers i such that the layers SVHOE presents an alternating structure of grating and buffer layers. The filter has a diffraction efficiency control, preferably based on the ECD effect, for selectively varying the diffraction efficiency .eta. in at least one grating layer i to select from the beam of radiation a narrow bandwidth centered about Bragg wavelength .lambda..sub.B.sup.i of grating layer i.

Abstract: A bright reflective liquid-crystal display element with high contrast which does not require a polarizer is provided together with a laminated retardation film applied thereto. Row electrodes are formed on the surface of an upper substrate, and on the surface of a lower substrate, a column electrode is formed. On top of the row electrodes and the column electrode, an alignment film is printed, and both substrates are subject to rubbing process from the right side of the paper face to the left side. Then, these substrates are joined together to form a blank cell. Chiral nematic liquid crystals are made by mixing a trace of chiral dopant to nematic liquid crystals, and 1% of black dichroic dye made by mixing a several colors of anthraquinone dichroic dye is dissolved in the chiral nematic liquid crystals to form guest host liquid crystals. The gest host liquid crystals are injected into the blank cell, thereby forming a liquid crystal panel.

Abstract: A SAR radar has an optical processor which uses an electrical-signal-to-light modulator. The modulator includes a tapped delay line which may be either analog or digital, and the signals tapped from the delay line are applied to an array of temporary storage elements, which in the case of analog signals may be a capacitive sample-and-hold, or for digital signals may include storage registers. In order to improve the signal-to-noise ratio (SNR) by comparison with a processor using an acoustic modulator, the signals tapped from the delay line are sampled at a display sampling rate, which is very low by comparison with the signal sampling rate or the highest frequency of interest, and the sampled signals are held until the next following display rate pulse. The signals held in the temporary storage elements are applied to the modulator elements, so that the optical pattern remains fixed for relatively long periods of time during which the optical processing can integrate photons for improved SNR.

Abstract: A display system having a greyscale control arrangement for controlling light output from a plurality of optical fibers includes a light source effective for supplying a high brightness light output to the input ends of the plurality of optical fibers. A plurality of piezoelectric shutter members are disposed adjacent the light delivery ends of the optical fibers and are effective for controlling the delivery of light output through the optical fibers as a function of the on or off condition thereof. The delivery ends of the optical fibers are disposed relative to one another so as to form a plurality of display pixels. At least two of the optical fibers are combined to form each of the pixels. The diameters of the at least two optical fibers that make up each pixel are different thereby allowing that at least four different greyscale levels can be achieved for each display pixel.

Abstract: An array of M.times.N electrodisplacive actuators is prepared by:(1) forming a multilayered ceramic structure having M layers of a first conductive metallization and M+1 layers of an electrodisplacive material;(2) obtaining a composite ceramic wafer by slicing the multilayered ceramic structure in a direction normal to the layers of the first conductive metallization;(3) providing a plurality of regularly spaced horizontally directional trenches running parallel to each other wherein each of the trenches is located at an equidistance from two adjacent layers of the first conductive metallization;(4) depositing a second conductive metallization;(5) preparing N-1 regularly spaced vertically directional cuts on the composite ceramic wafer prepared using steps (3) and (4) to thereby obtain the array of M.times.N electrodisplacive actuators.

Abstract: A two-dimensional modulator array for modulating a plurality of light beams. The modulator array is comprised of a plurality of stacked wafer layers. Each of the wafer layers have a linear array of transversely driven Pockels modulators. The Pockels modulators are formed by placing a plurality of electrodes over a top surface of an optical material and extending the electrodes over a beveled edge of the optical material. A ground plane resides on the bottom surface of the optical material. Conductive end reflectors are associated with each of the modulator electrodes. These end reflectors reflect the light beams back through the wafer. Electrical attachments are connected to the ends of each electrode for controlling the modulation for each electrode. Thereby, separate light beams can be individually modulated.

Abstract: A deformable media spatial light modulator utilizes a transmissive deformable media disposed between a deformable transmissive conductor and a substrate. A plurality of electrodes are affixed to the substrate. A potential control is provided to control the potential difference between each electrode and the conductor. A wavefront to be modulated is incident upon the transmissive conductor, traverses the media and is incident upon a reflector, reverses direction, traverses the media a second time and exits the modulator. By allowing the wavefront to be modulated to traverse the media, several enhancements occur including an increase in sensitivity. The increase in sensitivity exhibits a dependence upon the index of refraction of the media.

Abstract: A surface deformation type spatial light modulator is electronically addressed by an active matrix array affixed to a second surface of an insulating substrate. Optically reflective electrodes are affixed to the substrate. Each electrode is electrically connected to a respective electronic addressing element by a feedthrough. Overlapping each electrode is a transmissive deformable media layer. Affixed to a first media layer face of the media layer is a transmissive conductor. A potential control is provided to control the potential difference between each electrode and the conductor in accordance with an information bearing signal. A wavefront to be modulated traverses the media, impinges on the electrodes, traverses the media layer a second time before exiting the modulator. Several advantages exist in the invention including increasing the modulation sensitivity of electronic addressed surface deformation type spatial light modulators.

Abstract: A light modulator for use with a laser or laser diode array such that the light from the laser is imaged on a light modulator having a row of light modulating elements, either of the reflectance or transmittance type. The light modulator is imaged onto a light-sensitive material and the image is scanned line by line on the light-sensitive material. Control circuitry is provided to control the relative movement between the light modulator and the light-sensitive material that may be either in planar form or wrapped out the circumference of cylindrical drum.

Abstract: A phase-contrast DMD based image system 36 for projecting an amplitude and phase modulated image. A flexure beam DMD array 34 is used to allow analog phase modulation of reflected light 38. The phase modulation is converted to amplitude modulation by the phase-contrast imaging optics including a phase plate 42. The resulting amplitude modulated wave is flicker-free and does not need to be synchronized to optical image sensors.

Abstract: A display system (20) that uses multiple SLMs (25) to enhance horizontal or vertical resolution, or both. For example, to approximate a two-fold increase in horizontal resolution, the input data is sampled at a doubled rate, and each SLM (25) receives every other sample. Each SLM (25) generates an image, and the two images are partially superposed with a horizontal offset and simultaneously displayed. The resulting output image has a perceived resolution that approximates that of an image generated by an SLM with twice as many pixels per row.

Abstract: An interferometric switch for spatially switching either linearly polarized or unpolarized externally derived beams of substantially coherent light includes an optical input unit for dividing an externally derived light beam into a constituent beam pair. An optical phase modulating device includes a nematic liquid crystal pixel for selectively shifting the relative phase of the constituent beam pair. An output unit cooperates to combine respective components of the constituent beam pair along coincident collinear paths so as to form a respective output light beam directed along a selected one of first and second output axes, according to the relative phase imparted by the phase-modulating device. The phase modulating device may comprise a cascading arrangement of pixel stages which can respectively provide a selected incremental phase-shift to each constituent beam passing therethrough.

Abstract: The invention relates to a programmable transverse filter required for the matched filtering of signals with very wide passband. The signals to be filtered modulate one or more optical carriers (F1) in a modulator (MOD). Each carrier is distributed over several channels by a distributor (DIV). A delay creation circuit (CR1 to CRn) is provided in each channel. These channels are next summed after having been correctly delayed and assigned a coefficient characteristic of the signal to be detected.

Abstract: Operation results for all combinations of input optical signal values to be operated are previously determined and substantially parallel light beams reflecting the operation results for all combinations are generated. Selectors for selecting transmission area of the input light beams in accordance with digital information born by optical signals are arranged for the respective optical signals along the direction of propagation of the light beams. Through the logically cascade-connected selectors, an optical signal corresponding to a combination of current input optical signals is selected from the operation results for all combinations.

Abstract: A raster output scanning system is disclosed which utilizes a single light source, an electro-optical device and a beam-splitter to generate two light beams in order to simultaneously scan two adjacent scan lines. Two different trains of pixel information are used to control the intensity of the laser light source and the degree of the polarization of the electro-optical device in order to modulate the two light beams with two separate trains of pixel information without using a modulating device. Each of the two light beams exiting the beam-splitter is modulated in accordance with one of the two trains of pixel information.

Abstract: The invention pertains to an electromagnetic wave modulator comprising a quantum well semiconductor structure having two adjacent wells, the coupling of which is modified under the effect of an electrical field by the use of the phenomenon of anti-crossing of resonating levels. With this type of modulator, it is possible to attain 20% of modulation (as in the prior art) but with heightened sensitivity to the electrical field and a very short response time.

Abstract: Full complex spatial light modulation is enabled by an optically additive combination of the actions of separate and independent spatial light modulators, even though the independent modulators can each express only a one-parameter subset of complex values called its operating curve. Similarly the operating curve of a single modulator can be shifted (biased) by optically adding a constant complex value.

Abstract: There is disclosed a line printing system of this invention which utilizes an array of asymmetrical Fabry-Perot light valves for simultaneously transferring all pixel information of one raster line onto a photoreceptor. The number of elements of the light valve array used in this invention is equal to the number of pixels on a raster line. The pixel information is applied to elements of the light valve array in a parallel format with information representing each pixel applied to one elemental light valve of the array. The array is illuminated by a wedge-shaped incident light beam forming a focussed line image. Depending on the information state of each pixel, each corresponding element will be activated to absorb incident light or left in its neutral state to reflect the light. Light reflected by neutral elements will be directed onto the photoreceptor. In this fashion, the photoreceptor simultaneously receives the pixel information for the entire raster line.

Abstract: A method of linearizing a modulator (1) having two parallel-coupled sub-modulators (2, 3). The complete transmission function of the modulator includes parameters which relate to power division (A, 1-A) of a non-modulated carrier wave (P.sub.in) and a relationship (B) between the activation degree of the sub-modulators (2, 3). The transmission function is simplified and series-expanded with two higher-order terms, each having a respective coefficient. An expression for intermodulation distortion is calculated with the aid of the series-expansion and with control signals (V1, V2) having two or three frequencies. The signs of the coefficients are determined so that the terms having these coefficients will mutually counteract their respective distortion contributions, and limited search regions for the parameters (A, B) are calculated with the aid of the sign-determined coefficients.

Abstract: An optical filter device comprised of two parallel arrays of lenses. Each lens in the first array faces a lens in the second array to form a pixel. Lens pairs in a pixel are separated by the sum of their focal distances and include in their common focal surface a "smart" layer for modulating light passing through the focal surface. Preferred embodiments include car rear view mirrors, sunglasses, glasses for night driving, laser goggles, nuclear goggles, sun visors, sun shields, windshields, space suit helmet visors, optical instrument protection devices, window filters and energy conservation devices.

Abstract: An optical calculating apparatus which can perform operations by optically controlling incident light and hence perform such operations very rapidly and in parallel is provided. A unit component is composed of a pair of electrodes and a modulation material layer sandwiched therebetween and consisting of a material such as a liquid crystal in which the molecular struture is twisted by an applied electric field to change the transmission amount and transmission direction of light incident from the outside, thereby performing a modulation. The optical calculating apparatus is constructed by stacking or laminating such unit components in n stages. The unit component of the first stage has a structure in which the modulation material layer is sandwiched between a pair of the electrodes and input light enters into the modulation material layer in the direction perpendicular to the arrangement direction of the electrodes.

Abstract: An improved apparatus for viewing transparent film prints, such as X-rays, mammograms and sonograms, is provided, which apparatus includes a light source, a viewing stage and an array of light valves to selectively prevent the transmission of light from the light source to certain areas of the viewing stage. The apparatus allows an operator to more efficiently and accurately discern detail in the analysis of transparent film prints.

Abstract: An optically bidirectional electrically controlled optical switch having reduced light loss includes an electro-optic crystal having one set of fast and slow optical axes and having at least two light paths for receiving light beams through the crystal, the crystal exhibiting electric field induced birefringence such that a light beam passing through the crystal along a light path and having a plane of polarization oriented in a first direction may have its plane of polarization switched from the first direction to a plane of polarization oriented in a second direction. Beam splitting polarizers are disposed at each end of the electro-optic crystal and optically aligned with the two light paths. The beam splitting polarizers split the optical beam into two light beams having planes of polarization oriented in the first and second directions when transmitting light to the two light paths and combine the two light beams into a single light beam when receiving light beams from the two light paths.

Abstract: A device for compensating for changes in temperature and strain in electro-optic modulators without altering the voltage field effects. Devices for modulating light intensity in response to a varying electrical signal are particularly useful with optical fiber information sensing systems. Such modulators basically receive a light signal, collimate and polarize the light, then pass it through a wave plate to cause circular polarization. The light signal then is passed through a modulator material which rotates the beam polarization in response to varying voltage signals imposed on the modulator. Unfortunately, changes in temperature and strain also change the state of polarization. I have now found that by transmitting the light signal through two equal crystals in series that are rotated 180.degree. from each other, a uniform strain or temperature change will result in canceled polarization effects. Thus, effects of changes in temperature and/or strain are canceled without affecting the voltage field effects.

Abstract: There is provided an optical system for a spatial light modulator. The system comprises a light source for emitting an unpolarized light, a separator for separating a first linearly polarized light having a specified plane of polarization from the unpolarized light and polarizer for rotating the plane of polarization of the first linearly polarized light at a specified angle different from the specified angle to obtain a second linearly polarized light, wherein the second linearly polarized light is adopted as a reading light. Also provided is a method of photomodulation, comprising the steps of separating a light in the region of a specified wavelength from an unpolarized light, separating a first linearly polarized light having a specified plane of polarization from the light and obtaining a second linearly polarized light by rotating the plane of polarization of the first linearly polarized light at a specified angle.

Abstract: In a raster output scanner, a system for using one original beam and one facet of a rotating polygon to generate a scan line which can be turned on to have three levels of intensity. The original beam is first separated into two beams in a beam splitter. The resultant beams are polarized ninety degrees apart, and directed to the modulator. The beams are a sufficient distance apart so that the A/O modulator can modulate each beam with a minimum of crosstalk. The output beams are then brought together and combined into one beam without optical interference because the beams are polarized ninety degrees apart. The beam can have several levels of intensity and be used to create several levels of gray scale at the output.

Abstract: In a raster output scanner, a system for using one original beam and one facet of a rotating polygon to generate two consecutive scan lines. The original beam is first separated into two beams in a beam splitter. The resultant beams are polarized ninety degrees apart, and directed to the modulator. The beams are a sufficient distance apart so that the A/O modulator can modulate each beam with a minimum of crosstalk. The output beams are then brought together to within one scan line separation by a beam recombiner, which is a reversed beam splitter. The beams can be brought together to this close proximity without optical interference because the beams are plarized ninety degrees apart.

Abstract: A multiple-stage optical Kerr gate system for gating a probe pulse of light. In a first embodiment, the system includes at least two optical Kerr gates, each Kerr gate including a polarizer, an optical Kerr cell actuable by a pump pulse, and an analyzer. In a second embodiment, at least one of the Kerr cells may be eliminated by arranging the respective sets of polarizers and analyzers so that they share a common Kerr cell. Gated pulses obtained using the present system typically have a signal to noise ratio that is at least 500 times better than that for gated pulses obtained using a single optical Kerr gate system. The system of the present invention may also include means for causing the pump pulse to arrive at the second Kerr cell (in the case of the first embodiment) or at a single Kerr cell a second time (in the case of the second embodiment) non-synchronously with the arrival of the probe pulse thereat.

Abstract: An optical space switch includes a polarization controller, a beam splitter, a first reflection block and a second reflection block. The polarization controller has a first mode and a second mode. The polarization controller maintains the polarization of input light in the first mode and changes it by 90.degree. in the second mode. The first reflection block includes a quarter wave plate and a light path changing element. The input light from the polarization beam splitter is reflected by the first reflection block. During this time, the input light passes through the quarter wave plate twice. Thus, the polarization of the input light is changed by 90.degree.. Further, the light path of the input light is shifted by a predetermined distance by the light path changing element. The second reflection block has a quarter wave plate and a mirror. The second reflection block receives the input light from the polarization beam splitter, and returns it thereto.

Abstract: The concept of using only a component of an applied electric field to control the electrooptic response in each element of a multi-crystal electrooptic modulator comprising a matched grouping of birefringent electrooptic elements is disclosed. The foregoing concept permits the orientation of the polarization eigenvectors of the grouped elements to compensate for the effects of the static birefringence of the material comprising the elements while retaining the use of parallel applied electric fields and eliminating the need for an interposed optical rotator or waveplate.

Abstract: A crystalline silicon 1.1-20 micron spatial light modulator has an X-Y array of p-i-n pixels which are selectively foward biased at low voltages to induce substantial phase shifts in the optical wavefront, by the dual injection of holes and electrons through the silicon body and parallel to the light being modulated. The easy-to-fabricate SLM, is less sensitive to changes in temperature and wavelength, and can modulate light regardless of its state of polarization.

Abstract: An electromagnetic radiation beam scanning system for scanning an object with an electromagnetic radiation beam. The scanning system comprises first and second beam-narrowing devices which are arranged so as to have elongated light-transmission regions, respectively, and which are overlapped each other so that the light-transmission regions intersect each other. Each of the beam-narrowing devices includes a light modulation layer showing an electro-optic effect, first and second electrodes disposed so as to sandwich the light modulation layer, first and second polarizers disposed so as to sandwich the light modulation layer and a power source for applying voltages to the first and second electrodes. The light modulation layer combined with the polarizers forms the elongated light-transmission region in response to application of the voltages to the first and second electrodes due to the power source so as to produce a narrowed beam when a light beam is incident thereon.