Abstract: An impact resistant antireflection coating for an optical element which mitigates damage to the optical element when an air flight system having the optical element is flown through a high velocity droplet impact medium is described. The coating comprises a material having a relatively high modulus of elasticity compared to the modulus of elasticity of the material of the optical element. The coating is deposited to a half wavelength thickness at a wavelength which must be maximally transmitted through the optical element. A quarter wavelength antireflection coating layer at the wavelength which must be maximally transmitted through the optical element is then disposed over the impact protection coating layer. The material of the antireflection coating is preferably of a high modulus of elasticity material having a refractive index which is intermediate the refractive index of the material of the base layer and the medium through which the airborne system is flown.

Abstract: Spatial light modulation (22) in a III-V single crystal (12), e.g., gallium arsenide, is achieved using the photorefractive effect. Polarization rotation created by beam coupling is utilized in one embodiment. In particular, information (16)on a control beam (14) incident on the crystal is transferred to an input beam (10), also incident on the crystal. An output beam (18) modulated in intensity is obtained by passing the polarization-modulated input beam through a polarizer (20).

Abstract: A supported thin metal hologram is formed and mounted on a substrate using an adhesive. In a preferred aspect, the hologram is covered with a transparent resin which preferably is identical to the adhesive.

Abstract: New light-polarizing articles (preferably in film form) are based on a polymer matrix which polarizers based on a polymer matrix which is constructed from polar or nonpolar monomer units or mixtures thereof, characterized in that polyacetylene is included as light-polarizing substance, said polyacetylene being obtained by polymerizing acetylene in solutions of said polymer matrix and thereafter processing the resultant polyacetylene/polymer solutions into polarizers.

Abstract: An improved holographic rear window stoplight is provided and includes a hologram member laminated to the rear window surface. Single or multiple hologram layers may be provided. The hologram layers can have a diffraction grating developed in a position relative to the other diffraction grating to provide a folded reflection of light from a source of light of an appropriate wavelength band to indicate a stoplight from a predetermined angle. Alternatively predetermined indicia can be selectively displayed in either a single or multiple layer configuration. The reflection hologram member is transparent when not in use to all observers and remains transparent to the driver even when in use, and thereby prevents any blocking of his field of view.

Abstract: A method for self-referencing holography makes use of multiple object illuminations with different and non-uniform intensity of radiation to produce multiple holograms from the scattered radiation. Analysis of the multiple holograms provides an unambiguous image of the object.

Abstract: A colored article comprises a workpiece having a surface producing a color by light interference. The surface is defined by forming a reflective surface and coating the reflective surface with a composite layer of SiC and SiO.sub.2 having an SiO.sub.2 ingredient ratio of 5 to 80% by weight and a thickness of 200 to 3000 .ANG. or with a composite layer of Si.sub.3 N.sub.4 and SiO.sub.2 having an SiO.sub.2 ingredient ratio of 5 to 80% by weight and a thickness of 400 to 4000 .ANG..

Abstract: In a diffraction grating grooves having at least two kinds of grating constants are alternately arranged so as to repetitive at a constant period.

Abstract: Aberration in an image reflected from a warped surface such as an automobile windshield is corrected by providing an image to the windshield which is predistorted to compensate for the aberration. The predistorted image is created and stored in a hologram by a recording technique wherein a first transmission hologram which records the virtual image of an object is illuminated with a conjugate beam. The beam which is transmitted by the first transmission hologram is reflected off the windshield onto a second hologram recording plate, which is also illuminated by a reference beam passed through the windshield. The desired predistorted image is thereby stored in the second hologram recording plate.

Abstract: An optical imaging system comprised of successive planes of massively parallel elements, wherein each element handles only a small component of the resulting image is described. The resulting image is a composite or integral image made up of typically several hundred thousand component points each individually generated by a separate serial optical processing stream.

Abstract: An apparatus for constructing a hologram of one or more two-dimensional images by displaying the images on a variable-reflectance device. An object beam of coherent radiation is directed at the variable-reflectance device to be redirected by the device to a holographic plate, and a reference beam of coherent radiation is directed at the holographic plate to produce, in combination with the redirected object beam, a holographic interference pattern on the plate to form a hologram on the plate. A masking device, preferably electronic, may be provided to selectively expose successive portions of the plate corresponding to successive ones of the images to form a multiplex hologram on the plate.

Abstract: A process for the production of optical elements which comprises forming on a substrate a light-sensitive film containing at least a photoreactive compound, and selectively exposing the film to radiation to cause migration of the unreacted compound from an unexposed area to an exposed area by the exposure. The present process is particularly useful in the low-cost mass-production of various micronized optical elements such as plastic microlenses and arrays thereof, optical waveguides, diffraction gratings, and holograms, for example. An optical device comprising the optical elements of the present invention is also disclosed.

Abstract: A hologram is fabricated by opening a volume phase reflection hologram formed in a recording medium such as a positive photoresist. The opening occurs by forming a second hologram, such as an off-axis hologram, in the same recording medium. The opening hologram can be replicated in metal and the metal can be used to emboss the fringe pattern of the opened hologram into plastic. A full range of colors in the visible spectrum may be obtained by metallizing the embossed plastic structure and then by overcoating it with appropriate clear dielectric layers.

Abstract: A self-tuning optical notch filter is employed to separate coherent from noncoherent radiation in an overall beam. The presence of coherent radiation is detected, preferably with an interferometer, and the frequency of the detected coherent radiation is determined. An electrical control signal is generated with a frequency corresponding to that of the coherent radiation, and causes an optical filter to filter out the coherent radiation from the beam. In the preferred embodiment the optical filter is a Bragg cell, and the electrical control signal is applied to an electro-acoustic transducer which furnishes an acoustic control signal to the Bragg cell.

Abstract: A short pass filter is disclosed which exhibits high transmission in the infrared and/or visible region of the electromagnetic spectrum and which has high rejection in the microwave portion of the spectrum. The filter generally consists of a substrate of semiconducting material, for example, n-type germanium which has been doped with a suitable dopant or grown with impurities to provide a substrate with a known conductivity. A metal mesh is placed either on one or on both surfaces of the substrate, or is buried within the substrate. The combination of the semiconducting material and metal mesh produce a filter which will transmit infrared and/or visible radiation while rejecting microwave radiation through absorption and reflection.

Abstract: The disclosure relates to a wide spectral band objective refractive apochromatic lens system capable of operation with infrared light in the 3 to 12 micron range with good color correction simultaneously. The lens system includes three lenses, the first lens being positive and formed of Texas Instruments 1173 glass and the second and third lenses being negative and formed of germanium and zinc sulfide respectively. The germanium lens has a power approximately 0.44 that of the 1173 glass lens and the zinc sulfide lens has a power approximately 0.22 that of the 1173 glass lens.

Abstract: The wavelength selection device comprises a substrate (1); and a deflectable wavelength selection member constituted by a diffraction grating (10) provided by a torsion member (6) mounted to the substrate (1). A pair of electrode (4,5) are responsive to a control current to cause the torsion member (6) to deflect whereby radiation centered on a predetermined wavelength is selected from radiation having a number of wavelengths impinging on the selection member (10) by setting the selection member (10) at a predetermined angle to the incoming radiation.

Abstract: Such system can include, in the first plane, a first optical device for producing converging radiation from incident, substantially parallel radiation passing through the first optical device and, in a second plane, substantially parallel to the first plane, a second optical device for receiving, as incident radiation, converging radiation from the first optical device and for recollimating or reducing the degree of convergence of this incident, converging radiation as it passes through the second optical device.

Abstract: The invention relates to an optical relay which includes a target plate of an electrically insulating material and allowing the light to pass in a manner dependent on the electric field parallel to the direction of propagation of this light, means for scanning a first surface of this target plate by means of an electronic beam (34) controlled by a wehnelt electrode (34), an anode (38), an optically transparent plate (38) which is electrically conductive and which receives the visual information electric signal from an amplifier which supplies a video signal. The optical relay operates with a further amplifier (52) which applies a small overmodulation supplied by the video signal to the wehnelt electrode in order to enhance the readability. The overmodulation may be automatically controlled by means of a picture integrator.

Abstract: An optical isolator comprising a cylindrical magnet magnetized in a direction parallel to the axis of rotational symmetry thereof, a Faraday rotator disposed in a center space of the cylindrical magnet, a pair of beam splitters capable of serving as a polarizer or an analyzer arranged on both sides of said Faraday rotator with inclination of 45.degree. relative to each other, characterized in that the outer diameter Do, the inner diameter Di and the length L of the cylindrical magnet are in the range defined by ##EQU1## where .alpha.=Do/Di. In the case of a multi-stage optical isolator, the Faraday rotators and the beam splitters are arranged alternately in tandem, and any two adjacent cylindrical magnets are arranged with their magnetic poles of the same polarity facing each other.