Abstract: In a semiconductor layer which has in a semiconductor bistable etalon a refractive index variable, as a result of absorption by excitons, with the intensity of an optical beam incident thereon, an optical guide for the optical beam is surrounded by a cladding portion including atoms which reduce the refractive index in the cladding portion relative to the optical guide and serve as recombination centers for free carries produced by decomposition of the excitons. The semiconductor layer may be either a superlattice layer, such as a GaAs-GaAlAs layer, or a bulk semiconductor layer, such as a GaAs layer.

Abstract: A shutter having no moving parts and intended for use at infrared wavelengths includes a thin film of vanadium dioxide deposited on an insulative layer of silicon oxide that has been grown on a thin substrate of semiconductive silicon. The layers are in good thermal contact, but the vanadium dioxide film is electrically insulated from the silicon substrate. The vanadium dioxide film is heated by passing a heating current through the semiconductive substrate, and is cooled by radiation. The resistance of the vanadium dioxide film is sensed continuously, and is used for turning on and turning off the heating current.

Abstract: An electrochromic display device which comprises a display electrode comprising a transparent substrate, a transparent electrode formed on an inner surface of the transparent substrate and an electrochromic material layer for display made of tungstgen oxide and formed on the transparent electrode; a counter electrode comprising a substrate, a conductive layer formed on an inner surface of the substrate and an activated carbon fiber cloth bonded to the conductive layer with a conductive adhesive; and a spacer provided beween the display electrode and the counter electrode with their inner surfaces facing to each other to define, between them, an electrolyte chamber, which is filled with an electrolyte comprising LiClO.sub.4 dissolved in propylene carbonate containing water and an acid, which device has an increased original injected charge and good maintenance of the injected charge after prolonged storage.

Abstract: This specification is directed to electrochromic optical shutter (10) in which an electrochromic material (12), an ion conductor (14), and a counter electrode (16), in that order, are sandwiched between visibly transparent electrodes (18-18). The shutter is improved by forming the counter electrode from a nickel oxide applied to, as a base therefor, either the ion conductor or one of the transparent electrodes. The material is applied by a pyrolytic spray process in which a solution containing nickel as a pyrolyzable organic salt dissolved in an organic medium is sprayed on the base. The base has been previously heated to a temperature sufficient to pyrolyze the sprayed material and form a nickel oxide counter electrode layer.

Abstract: An electro-optical device is arranged as a Fabry Perot etalon comprising two mirrors and a central region. The mirrors are multilayer heterostructures of Al.sub.x Ga.sub.1-x As semiconductor materials where x alternates between 1.0 and 0.3. The central region may be a multiple quantum well structure of Al.sub.x Ga.sub.1-x As where x alternates between 0 and 0.3. The etalon material doping is non-uniform so that it is electrically a semiconductor device with a biasable central region. The optical path length in the central region is electric field dependent, and the etalon transmission or reflection is accordingly modulatable by varying the central region bias. The mirrors may be heavily doped and of opposite conductivity type with the central region undoped. This provides a PIN diode. Light incident on the etalon executes multiple transits of the central region.

Abstract: A device for selecting a light source among a plurality of light sources, for measuring the wavelength characteristics of an optical element comprises: a signal source which generates a modulating signal; a change-over switch connected to the signal source; a plurality of light sources different from each other in wavelength, connected to the outputs of the change-over switch; a coupler coupling the respective outputs of the light sources; a detector for detecting the respective outputs of the light sources; a filter which passes only a component of the output of the detector corresponding to the modulated optical output of a selected light source; and an indicator for indicating the measured wavelength characteristics of a measured optical element. The change-over switch is operated to selectively connect the signal source to a selected light source to modulate the optical output of the selected light source by the modulating signal of the signal source.

Abstract: The invention relates to an electrochromic (EC) device having oppositely arranged two substrates at least one of which is transparent and each of which is coated with an electrode film on the inside surface, a first EC layer which is formed on the electrode film of one substrate and is formed of a transition metal oxide that takes on color in its electrochemically reduced state, such as WO.sub.3, an opposite EC layer which is formed on the electrode film of the other substrate and is formed of another EC material, such as a polytriphenylamine that takes on color in its electrochemically oxidized state, and an electrolyte solution which uses a nonaqueous solvent and occupies the space between the two substrates. According to the invention, the transition metal oxide layer contains such an amount of adsorption water that the concentration of water in the electrolyte solution in the device becomes more than 0% and not more than 0.3% by weight.

Abstract: Optical relay for projection television includes a target (12, 31) of an electrically insulating material which allows the light to pass in a manner depending on the electric field parallel to the direction or propagation of this light. An electron beam scans a first face of this target scanned by an electron beam and an anode (30) receives the secondary electrons emitted in response to the action of the beam. An optically transparent and electrically conducting plate 38 is provided against the second face of the target receive the electric signal conveying the video information. The target is made of a material which becomes ferroelectric, and a heat exchanger (18) is connected to a heat source which maintains the temperature of the target. In the normal mode of operation the target is formed by a useful central zone where it exhibits a single domain ferroelectric phase and a neutral peripheral zone, having a temperature much higher than the Curie temperature where it exhibits a paraelectric phase.

Abstract: Light emitted by a source arrives through a system of lenses and a first system of bars on the control layer of a control element. The light is reflected and refracted in keeping with local deformation of the control element nad then conducted through a concave mirror, a second bar system and a further system of lenses onto a projection surface. The image to be amplified is reproduced by means of a system of lenses on a photoelectric conducting layer in the control element. A control layer is a layer of gel and is located between two electrodes in an alternating electrical field, which may be affected by the photoelectric conducting layer. The electrode adjacent to the photoelectric conducting layer is electrically insulated relative to the photoelectric conducting layer and is in the form of a strip grid, the strips of which are connected alternatingly to one or the other pole of a source of alternating voltage. One of the poles is connected with the other electrode.

Abstract: Method and apparatus for optical phase conjugation, which apparatus is also known as a phase conjugate mirror, utilizes Brillouin enhanced four wave mixing in which a forward going pump wave and a backward going pump wave have frequencis which differ by twice the Brillouin frequency of the medium. The probe wave and the conjugate wave, which is obtained by Brillouin enhanced four wave mixing in the medium, have the same frequency, which differs from the pump wave frequencies by the Brillouin frequency of the four wave mixing medium. High reflectivity (gain) is obtained as a result of Brillouin resonance enhancement. The backward going pump wave is created from the forward going pump wave which is transmitted through the four wave mixing medium by stimulated Brillouin scattering in a Brillouin scattering medium having a Brillouin frequency twice that of the four wave mixing medium.

Abstract: A scanning optical device including a rotating polygonal mirror or oscillating mirror. Two acoustooptical devices are disposed along the path between the light source and the mirror and are set for respective time-constant angles of deflection to compensate for tilting of the mirror without introducing an offset.

Abstract: An electrochromic device consists of the layers: tin-oxide-coated glass; rare earth diphthalocyanine (REDPC); membrane electrolyte; REDPC; tin-oxide-coated glass. The REDPC is the electrochromic layer and contains a mixture of rare earths as obtained from a natural deposit without being individually separated. The REDPC is preheated to purify it and then sublimed into position as the device is assembled.The device is driven by a controller which is limited to the voltage range +2V to -1V, whereby only the colors red, green and blue are obtainable, that is, although the REDPC at -1.5V would show purple, this is deliberately foregone to prolong its life.The REDPC may be further mixed with tin phthalocyanine chloride or ruthenium, iron, zinc or cobalt phthalocyanine.

Abstract: A tunable resonant cavity filter structure is disclosed which includes an enhanced ground return internal to the cavity which effectively eliminates generation of deterioration wide band noise and optimizes unloaded Q as well as rending resonant frequency stable with vibration. In its preferred form, the enhanced ground return is in the form of a ground return clip with reliant radial projections that mate with the threads of the threadable tuning element used to determine final operating frequency. The radial projections are deflected in cantilever fashion so as to generate sufficient pressure to break thru any oxides in the tuning element threads and ensure metal-to-metal contact.

Abstract: The invention relates to an electrochromic (EC) display device having a transparent electrode layer coated with a first EC material which takes on color in its electrochemically oxidized state, such as Prussian blue, and an opposite transparent electrode layer coated with a second EC material which takes on color in its reduced state, such as WO.sub.3. For use in initial bleaching or coloration of one of the two EC layers, an auxiliary electrode is disposed in a marginal region of the space between the two opposite electrodes, and an electrolyte occupies the remaining space. An insulating covering permeable to ions intervenes between the electrolyte and the body of the auxiliary electrode, and an insulating layer substantially impermeable to ions intervenes between the auxiliary electrode body and each transparent electrode layer or the overlying EC layer to prevent leakage current.

Abstract: An electrochromic display device which comprises a display electrode comprising a transparent substrate, a transparent electrode formed on an inner surface of the transparent substrate and an electrochromic material layer for display made of tungsten oxide and formed on the transparent electrode; a counter electrode comprising a substrate, a conductive layer formed on an inner surface of the substrate and an activated carbon fiber material; and a spacer provided between the display electrode and the counter electrode with their inner surfaces facing each other to define, between them, an electrolyte chamber, which is filled with an electrolyte comprising a lithium salt and at least one of the tertiary alkyl ammonium salts and quarternary alkyl ammonium slats dissolved in a non-aqueous medium containing a small amount of water, which device has increased original injected charge which can last for a long time.

Abstract: A light radiator comprises a cylindrical optical conductor rod in which light rays are guided into the optical conductor rod from one end portion or both end portions thereof. The guided light rays into the optical conductor rod are radiated from the optical conductor rod in a radial direction. The optical conductor rod is divided into plural pieces in radical direction along its center line as a common line and the respective division surfaces are provided with a reflection surface.

Abstract: A magneto-optical light switching element comprising islands which are formed from an epitaxial layer on the basis of bismuth-substituted rare earth metal iron garnet, which layer is provided on a magnetically unordered, optically transparent, (111)-oriented garnet substrate, integrated heating resistors being provided on the islands which are surrounded by a coil, the epitaxial layer being grown from a melt which contains lead oxide and boron oxide as a flux, the boron content of the melt used for growing the epitaxial layer being in the range from 12.7 to 25 at % (cation content) and the coil being constructed as an integrated coil.

Abstract: In a semiconductor wafer stepper system, a reticle having an alignment mark positioned adjacent the center thereof and utilized to align each wafer in the stepper system, as well as to adjust the stepper software of the system.

Abstract: A nonlinear optical matrix multiplier includes a nonlinear optical medium with a first optical input beam impinging on the medium, the transverse spatial intensity of the first input beam being modulated by a first two dimensional matrix. A second optical input beam impinges on the medium, with the transverse spatial intensity of the second input beam being modulated by a second two dimensional matrix. An optical probe beam impinges on the medium, the first input beam, the second input beam, and the probe beam being oriented with respect to one another and with respect to the medium such that the beams interact within the medium by means of four-wave mixing. A diffracted output beam emerges from the medium, with the transverse spatial intensity of the output beam modulated by the product of the first and second matrices.

Abstract: An acoustic signal is launched as a surface acoustic wave (SAW) by a hyperbolically tapered transducer and then reflected into a bulk acoustic wave (BAW) by a tapered reflector. At each frequency the tapered reflector must satisfy the phase match conditions between the SAW and BAW as defined by their wave vectors. Let k.sub.B be the projection of the BAW wave vector on the surface, and let k.sub.S be the wave vector of the SAW. Then, if k.sub.G is defined to be the wave vector of the grid, i.e., k.sub.G =2.pi./d, where d is the periodicity of the reflecting strips at the frequency under consideration, the phase match condition is k.sub.G =k.sub.B -k.sub.S. A reflector designed to satisfy this condition will reflect the SAW into a BAW at any desired angle (as specified by k.sub.B). The laser beam is then Bragg scattered by the BAW in the usual manner. The advantage of this scheme is that the tapered transducer separates the acoustic signals spatially so no intermodulation products are formed.