Abstract: A process for producing a polyurethane plastics having photochromic properties, characterized in that the process comprises in a first step incorporating a reversible cleavage photochromic compound into at least one di-isocyanate compound or at least one polyol or a mixture of a di-isocyanate and one or more polyols or into any other component of a mixture which, when polymerized, will yield a polyurethane; combining the mixture from the first step with any other necessary components to enable polymerization to occur; and polymerizing the resultant mixture to form a polyurethane incorporating the said photochromic compound. The photochromic polyurethane plastics of the invention are useful as intermediate layers in glass or plastics laminates for architectural applications or for use in vehicle windows or roof-lights.

Abstract: A light beam deflection device comprises an acoustooptic element including a piezoelectric crystal base with a first flat surface and second and third flat surfaces each perpendicular to the first flat surface and opposite to each other and a transducer attached to the first flat surface of the piezoelectric crystal base and supplied with a deflection control signal, a first lens element having a first cylindrical surface forming a cylindrical lens and a first slanted flat surface opposite to the first cylindrical surface and disposed so that the first cylindrical surface faces the second flat surface of the piezoelectric crystal base, and a second lens element having a second cylindrical surface forming a cylindrical lens and a second slanted flat surface opposite to the second cylindrical surface and disposed so that the second cylindrical surface faces the third flat surface of the piezoelectric crystal base.

Abstract: Pane or foil with controllable transparency and light transmission comprises a layer configuration between two transparent carriers such as glass panes, foils or the like; transparent electrodes are disposed on the carriers; a tansparent electrolyte and an active polymer layer are disposed between the electrodes; the active polymer layer has light absorption in the visible spectrum range characterized by a variation in the case of a reversible chemical doping reaction; preferably an additional transparent layer is included to serve as reversible source for storage and yielding of ions, the additional layer is juxtaposed to the electrolyte.

Abstract: A method and apparatus for increasing the angular aperture of an acousto-optic dispersive light filter in which acoustic frequencies of differing frequencies are launched into a crystal at differing angles to each other. Input light phase matches with corresponding ones of the acoustic frequencies so that the angular aperture is enlarged.

Abstract: An electrooptical light shutter device for use in an optical printer apparatus, comprising a number of shutter elements arrange in the form of at least one linear array, each of the shutter elements having an electrooptical effect, a polarizer disposed on a light-incoming side of the array of the shutter elements, and an analyzer disposed on a light-outgoing side of the array of the shutter elements, wherein the shutter elements have respective shutter windows through which light is to be passed selectively and the shutter windows are arranged to be overlapped by one another in a direction substantially perpendicular to the direction in which the shutter elements are arranged.

Abstract: An electro-optical phase modulator. The electro-optical modulator incorporates a stripline configuration with a bottom ground plane attached to the bottom surface of the crystal and a signal conductor that is affixed to the top surface of the crystal. The signal conductor is separatred from a top ground plane by a dielectric, usually air. The top ground plane also overhangs the sides of the crystal to lower the effective dielectric constant of the modulating signal that is applied to the signal conductor. In this way, the electric field established in the crystal by the modulating signal has a speed more nearly equal to the speed of the optical beam that passes through the crystal and is modulated by the electrical signal.

Abstract: An optical modulating method is provided which comprises heating a heat-sensitive medium comprising a polymeric substance and a liquid with a heat-generating resistor adjacent to the medium, thereby modulating the light incident on the medium at the heated region. The liquid may be heated to the critical solution temperature or higher of the constituent polymeric substance.

Abstract: Optically transparent quantum well structures, such as GaAs/Al.sub.0.5 Ga.sub.0.5 As, are electrically biased to produce a quadratic nonlinear optical susceptibility, the sign of which depends on the direction of the applied electric bias field. This quadratic nonlinear optical susceptibility is particularly useful for enhancing three-wave interactions especially when the applied bias field is made spatially periodic to obtain quasiphasematched interaction. Also, the quantum well material is preferably arranged in an optical waveguide for guiding the interacting waves to reduce unwanted diffraction effects.

Abstract: The output of an optical device which involves a stimulated brillouin scattering (SBS) gain medium is enhanced over a range of input beam intensities by providing a gain medium which has a given SBS gain for a given input beam intensity, and modifying the gain medium to reduce its SBS gain coefficient. By lowering the SBS gain coefficient, SBS dominance and suppression of stimulated Raman scattering (SRS) can be mitigated, and the output fidelity of a phase conjugation system with respect to its input can be significantly enhanced. Mechanisms for reducing the SBS gain coefficient include increasing the medium viscosity, thermal conductivity and/or diffusion coefficient, or causing the medium relaxation zone to coincide with the frequency of the phonons involved in the SBS process. Two different media can be mixed together in varying proportions to progressively modify the overall medium SBS gain as the input beam intsnsity is progressively changed.

Abstract: A scanning system and method for optically measuring parameters such as dry basis weight, basis weight and moisture content of fibrous sheets during manufacture. The system includes a first track that extends generally parallel to one face of a traveling web in the cross direction; a stationary light source arranged to direct collimated light generally parallel to the first track; a first reflector that travels along the first track and focuses the collimated light against the adjacent face of the web; a second track that extends parallel to the first track adjacent the opposite face of the web; a second reflector that travels along the second track and collects and collimates rays that are transmitted through the web; and stationary light detectors that detect the intensity of the collected rays at least at two selected ranges of wavelengths to measure the absorption properties of the traveling web at selected locations.

Abstract: An optical bistable photorefractive crystal device is provided in which a photorefractive crystal disposed between two mirrors is uniformly illuminated by a light beam, a signal beam being focused on a given portion of the crystal to cause bistable switching of this portion inside the crystal.

Abstract: A compound is disclosed which excels in thermal resistance and acidproofness, fits application on a surface and fabrication, and exhibits both photochromism and electrochromism.

Abstract: A planar dimmer comprising a transparent base, a dimming part, capable of dimming, disposed on the base, the dimming part comprising a first electrode layer formed on the base, a second electrode layer set facing the first electrode layer, a coloring part disposed between the two electrode layers, and colors or discolors in response to the stimulus from the two electrode layers, and a conducting part disposed between the base and the first electrode layer in such a way as to be in contact with the first electrode layer in order to apply a uniform voltage throughout the first electrode layer.

Abstract: An apparatus and method are disclosed for holding a generally cylindrical workpiece for honing or otherwise machining an internal bore. The workpiece is held by a gripping surface over most of the innermost turn of a spirally wound spring and coil. The workpiece is grasped circumferentially over its outer surface without excess contact pressure at any particular point. A tendency of the machining operation to rotate the workpiece serves to secure the workpiece more tightly in position by tightening the outer turns of the spring band coil. A rotatable tensioning member acts under the influence of a biasing spring to decrease the diameter of the innermost turn of the spring band coil to bring the gripping surface into contact with the workpiece. A method for adapting the work-holding apparatus to smaller or inrregularly shaped workpieces consists of molding an annular piece around the workpiece.

Abstract: A cover for car lamps comprising a transparent base and a transparent element with variable coloring intensity capable of coloring and discoloring by electric conduction, disposed on at least a part of the base.

Abstract: High speed optoelectronic devices which are suitable for use in an optical integrated circuit design. The devices comprise a monolithic planar structure wherein exciton-resonant light propagates along a single mode waveguide containing a single quantum well as the absorbing media. Optical absorption is controlled by the bleaching effect induced by free carriers whose electrical conduction makes possible optical detection and monolithic high speed, gate-controlled transistor structures.

Abstract: A light beam deflector according to the present invention comprises an acousto-optical element for deflecting a light beam at an angle of deflection which is dependent on the frequency of a drive signal applied thereto. This acousto-optical element has a deflection efficiency which is also dependent on the frequency of the drive signal. The frequency-dependence of the deflection efficiency is corrected by modulating the drive signal in amplitude with predetermined modulating data which are stored in the form of digital data and used to correct the characteristics so that the deflection efficiency of the acousto-optical element is substantially independent of the frequency of the drive signal.

Abstract: A gasdynamic gas flow forms a lightguide wherein an incident coherent light wavefront, such as a laser beam, is reflected to produce a backward-travelling phase conjugated light wavefront. The nonlinear optical phase conjugation process occurs when the incident light intensity is large enough to achieve the intensity threshold required to initiate the phase conjugation process.

Abstract: A novel optical system and method for coupling and mixing a plurality of beams which may originate from different optical sources and may be of different colors. There is provided deflection and steering of light beams with automatic (self-aligning) Bragg matching over a large beam deflection range which is not limited by the Brass condition. There is also provided a novel method of spatial light filtering and modulation, image color conversion, bidirectional beam interconnection for optical communication and combining and locking of laser sources.

Abstract: A rate of the proceeding of a shifting operation during an inertia phase is adjusted to a target value such that a transmission output torque varies without any rapid change during the inertia phase and agrees smoothly with an output torque value to be established after the gear shift at the ending of the inertia phase.