Abstract: Multiple quantum well (MQW) structures (12) are utilized to provide real-time, reliable, high-performance, optically-addressed spatial-light modulators (SLM) (10). The optically-addressed SLM comprises a vertical stack of quantum well layers (12a) within the penetration depth of an optical write signal 18, a plurality of space charge barriers (12b) having predetermined tunneling times by control of doping and thickness. The material comprising the quantum well layers has a lower bandgap than that of the space charge barrier layers. The write signal modulates a read signal (20). The modulation sensitivity of the device is high and no external voltage source is required. In a preferred embodiment, the SLM having interleaved doped semiconductor layers for driving the MQW photovoltaically is characterized by the use of a shift analogous to the Moss-Burnstein shift caused by the filling of two-dimensional states in the multiple quantum wells, thus allowing high modulation sensitivity in very narrow wells.

Abstract: An optical element comprises a gel layer exhibiting a light scattering property when heated and exhibiting transparency when cooled, and the gel layer is sandwiched between a transparent substrate and a transparent protective plate.

Abstract: A light beam deflection scanning method including the steps of: (a) finding data for cancelling distortion of a scanning track to be made on a surface of an object by a light beam focussed on the surface by a scanning lens, the distortion being caused by the lens; (b) directing the light beam at the surface through a scanning lens and deflecting the light beam in a main scanning direction; (c) detecting the position of the light beam on the surface; and the deflecting in step (b), deflecting the light beam in a subscanning direction by an amount based on the data, to thereby cancel the distortion of the scanning track.

Abstract: Method and device for controlling a beam off light (17), which is coupled in into a working layer (2) of electro-optical material and which is supplied to a working area (16). In a first optically conductive state the working area has a poling mode which differs from the one of the surrounding working-layer material (7), as a consquence of which other refractive indices will arise, due to which the working area will form a light waveguide through which the beam of light coupled in will be conducted (19) to a first glass fibre (22). In a second optically conductive state the working area has a poling mode which is equal to the one of its surroundings. Because of the fact that the refractive indices inside and outside the working area are not equal, the working area will not form a light waveguide, but (e.g.) a light insulator or a light reflector, by means of which the beam of light coupled in will be conducted to a second glass fibre (21).

Abstract: A display system includes a display medium which comprises a display layer providing a display area capable of converting coherent light into light of a shorter wavelength through a nonlinear optical effect and converting the coherent light into scattered light. The display area is illuminated imagewise with coherent light such as a scanning laser beam to form a display image with scattered light having a wavelength different from that of the coherent light at the illuminated part of the display area.

Abstract: A modulator enables the modulation of a wave in the medium infrared range by means of a signal modulating the amplitude of another electromagnetic wave in the near infrared range. The modulator comprises: a central layer such that the electrons of the conduction band have at least two permitted discrete levels of energy, the energy difference of which corresponds to a frequency close to the frequency of the wave to be modulated, and such that the holes of the valence band have permitted levels of energy such that the difference in energy between the permitted fundamental level for the holes in the valence band and the permitted fundamental level for the electrons in the conduction band has a value close to that corresponding to the frequency of the control wave.

Abstract: An acousto optic diffractive device including a transducer for launching acoustic energy into a crystal so as to maximize overlap of the acoustic energy within the crystal, and a light source for illuminating the crystal so that the light is diffracted by the overlapping acoustic energy. By operating an acousto optic diffractive device in resonance, the amount of power required to drive the acousto optic diffractive device is significantly lowered, without adversely affecting the wavelength pass band of the device.

Abstract: This invention is directed to a method for patterning colorable areas of an electrochromic device.The device comprises two substrates and therebetween: one electrode layer; an electrochromic layer; an insulator material which is (i) non-ionically conductive and (ii) electronically insulating; a solid ion conductive material; and another electrode layer, at least one of the one electrode layer and the other electrode layer being transparent and each electrode layer being in contact with a respective one of the substrates. The ion conductive layer is adapted to communicate ions to and from the electrochromic layer upon application of a voltage across the electrode layes.

Abstract: An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Abstract: The invention concerns an electro-optical panel and, more especially, an intersection point transistor structure made with thin films, wherein there is provided a doubling of the line and column electrodes (LG, CL) by doubling elements (1g.sub.1, Col. 1, Col. 2), as well as a light barrier (EC) shielding a transistor. The invention also concerns a method for making a screen of this type. The invention can be applied especially in the technology of liquid crystal display panels.

Abstract: A device and corresponding method for optical phase conjugation using a stimulated Brillouin scattering (SBS) medium and resulting in a reduction in the (SBS) threshold level. An incident light beam is brought to a first focus in the SBS medium, and light transmitted through the first focus is brought to a second focus in the SBS medium. Light transmitted through the second focus is brought to a third focus, and so forth through N foci in the medium. The effective SBS threshold level is inversely proportional to the number of foci N, which may be located in separate SBS cells, or may be in a single cell through which multiple passes are made by means of appropriate reflective optics. Laser sources operating in multiple longitudinal modes are handled by spacing the foci at an intergral multiple of the laser resonant cavity length.

Abstract: This invention provides a magneto-optic garnet grown by liquid phase epitaxy on a nonmagnetic garnet substrate and having a composition of the following formula (1)Ho.sub.x Tb.sub.y Bi.sub.3-x-y Fe.sub.5 O.sub.12 (1)wherein 0.3.ltoreq.y/x.ltoreq.1.0 and x+y<3.0.According to this invention there is provided a magneto-optic garnet as a Faraday rotator for use in an optical isolator, optical circulator, etc., utilizing Faraday effect, which has a very large Faraday rotation coefficient, a small difference in lattice constant from a nonmagnetic garnet substrate, exhibits a mirror face without causing a film defect (or so-called pit), and has a small temperature dependency.

Abstract: A method of and a device for driving a light shutter having an electrooptical effect to polarize an incident light by applying an electric field to the light shutter. When the light shutter is made activate, an excessive electric field in addition to a half-wave electric field which is a specific one to polarize an incident light at 90.degree. in the static characteristics of the light shutter is applied to the light shutter initially, and subsequently, the half-wave electric field only is applied to the light shutter. To discharge the electric charge accumulated in the light shutter, no voltage is applied to electrodes each of which is provided on the wall of the light shutter so as to oppose each other subsequent to the application of the electric field until the next application thereof.

Abstract: An optical flip-flop comprises a phase-conjugating mirror; a one-way mirror having its reflective side facing the phase-conjugating mirror; a "set" light pulse directed towards the phase-conjugating mirror through the transmissive side of the one-way mirror for initiating a reference light beam which thereafter reflects continuously along an auto-collimating path between the mirrors; a normally transmissive optical gate along the path of the reference beam which is rendered nontransmissive relative thereto upon interaction with a "reset" light pulse; a plurality of filters positioned between the mirrors to prevent the self-starting of the reference beam therebetween; and means for deriving an output signal from the reference beam. An optical logic device comprises a plurality of such flip-flops sharing a single set of mirrors, whereby increased system compactness and simplicity is achieved.

Abstract: The present invention relates to a planar electrochromic dimmer used in dimming devices such as car sun roofs, and others having a structure comprising; a pair of bases, each comprising a transparent electrode film provided on each of a pair of bases, and arranged such that both transparent electrode films are facing each other, an electrolyte provided between the two electrode-equipped bases, a color-forming layer provided on at least one of the electrode-equipped bases, and a thin film with a visible ray transmittivity of 20-60% provided on at least one of the bases or the transaprent electrode films.

Abstract: This invention is directed to electrochromic devices having a color intensity gradient. Specifically the electrochromic device comprises two substrates and therebetween: one electrode layer; an electrochromic layer; an ion conductive material; and another electrode layer in that order. At least one of the electrode layers is transparent and each electrode layer is in contact with a respective one of the substrates. The ion conductive layer is adapted to communicate ions to and from the electrochromic material upon the application of a voltage across the electrode layers. The electrochromic material has a continuously decreasing thickness gradient in at least one region when measured normal to the plane of an electrode layer.

Abstract: A spatial light modulating device has a light modulating means which comprises a substrate which is transparent with respect to readout light and whose first surface is coated with a first transparent conductive film, an electro-optic crystal plate whose first surface being opposed to the first surface of the substrate is coated with a second transparent conductive film, an adhesive layer for bonding the substrate and the electro-optic crystal plate, and conductive substances disposed in the adhesive layer so as to electrically connect the first and second transparent conductive films.

Abstract: The present invention relates to the modulation of a phase conjugate beam. A writing beam is directed incident to a phase conjugate reflector. A modulating beam is also directed incident to the phase conjugate reflector for amplitude modulation of the phase conjugate beam. The modulating beam can also be steerable for effecting the amplitude of the phase conjugate beam according to spatial distribution so as to spatially modulate the phase conjugate beam. The phase conjugate modulation thus can be accomplished by opto-optical means and without modulation of or effect on the incident writing beam.

Abstract: An electromagnetic device comprising solid matrix layer, wherein micro-capsules containing suspension anisotropic particles are dispersed, and a means for applying electric field or magnetic field to the anisotropic particles. According to the present invention, not only range of transmittance of solar radiation can be much improved, but also a smart window of large scale having nonuniformity of thickness and nonuniformity of density of particles can be realized.

Abstract: A high intensity laser radiation protection system is characterized by the use of a thin film reflector structure which is operable to terminate transmission of optical signals to an optical sensor in response to high intensity laser radiation. The thin film reflector includes a glass substrate having a thin layer of radiation absorption material applied thereto with a thin layer of reflective metal film applied to the absorption layer. The absorption layer has a low melting and vaporization temperature, and the layer of metal film has a thickness affording passage of a limited amount of laser radiation to the absorption layer. When laser radiation having a predetermined intensity is received by the absorption layer, the absorption layer rapidly melts and destroys the metal film layer to terminate optical transmission to the optical sensor, thereby preventing damage to the sensor from the laser radiation.