Abstract: A system is presented for reconstructing blurred text on a word-by-word basis. The text is scanned and compared with a priori data concerning characteristics of the text, including zone characteristics of each letter of the alphabet. Comparisons are made between the line spacing of an image undergoing test and standard spacing. Such tests can also determine whether the image undergoing test was recorded while maintaining a tilted position. The blurred text is reconstructed on a word-by-word basis and may be displayed on a monitor. If the image undergoing test was photographed at an excessive focal length, the system is capable of detecting this and aborting analysis.

Abstract: A multi-layer structure for controlling the transmission laser radiation including an outer layer which is slightly absorbent to incident laser radiation and an intermediate layer which is substantially absorbent to incident laser radiation to achieve significant attenuation of on-axis transmission of laser radiation in an otherwise transparent structure.

Abstract: A multi-layer structure for controlling the transmission laser radiation including an array of polydispersing scatterers in an intermediate layer. The outer layer is made of a material which partially ablates when exposed to incident laser radiation, generating an irregular surface which initially scatters the incident laser radiation. The initially scattered radiation is transmitted to the intermediate layer containing the array of monofilament fibers which further scatters the laser such that combination achieves substantial attenuation of on-axis transmission of the laser radiation in an otherwise transparent structure.

Abstract: A multi-layer structure for controlling the destructive effects of laser radiation including means within the structure for conducting the heat generated in the outer layer by the incident laser radiation away from the outer layer to achieve significant mitigation of the destructive effects of the laser radiation in a transparent structure.

Abstract: A multi-layer structure for controlling the transmission of laser radiation including outer and intermediate layers absorbent to incident laser radiation. The outer and intermediate layers ablate under the influence of the incident laser radiation to achieve substantial attenuation of on-axis transmission in an otherwise transparent structure.

Abstract: Incorrectly assembled circuit boards become detected by directing interfering laser beams on the surface of a circuit board. Fringe patterns develop on the surfaces of electronic elements as well as the board proper. These fringe patterns are compared with those of a reference standard and anomalies become electronically detected.

Abstract: Holographic optical elements are utilized for discriminating between monochromatic, coherent radiation and broadband, noncoherent radiation in passive coherent radiation detection systems such as aircraft warning systems and submarine laser communication systems. Coherent laser light can possess an extremely high energy density, directivity, (i.e., collimation), and a very narrow wavelength band when compared to natural or man-made, broadband white light sources. The concentration of laser light energy by a holographic optical element at the detector stage is a consequence of its special characteristics. Moreover, equally important, the diffracted light distribution in the neighborhood of the detector possesses a unique, bright geometric pattern not readily obtained with noncoherent sources. This geometric pattern is used as a laser wavelength detector for determination of the incident angular direction of the laser beam, as well as a coherent/noncoherent light discriminator.

Abstract: A viewing window is equipped with a selective attenuator for a harmful incoming laser beam. The attenuator principally employs a holographic optical element which selectively deflects the laser beam where it may be absorbed or further deflected. Ordinary light passes undeflected so that it may be processed by optical equipment or a viewer.

Abstract: An elongated enclosure includes a number of apertures through which a film must be precisely viewed. A slider receives a removable film holder into which a film, such as a 35 mm slide is positioned. A precision recirculating bearing assembly provides accurate and smooth motion of the slider within the housing. A number of alignment components are located in the device to repeatedly and accurately position the film, relative to the apertures. Thus, a laser beam or optical axis can repeatedly and precisely pass through the same point of the image as it appears in a corresponding aperture.

Abstract: An optical correlator console for mounting and assembling the components of an optical correlator system in a unique stable, compact and functional configuration in which all of the components are mounted in a compact configuration on upper and lower sides of a base support plate. The components which do not ordinarily require accessibility are mounted below the support plate and the components which ordinarily require accessibility during operation and use of the optical correlator are mounted above the support plate. The lower side of the support plate mounts a laser source and a collimator along with several other incidental optical components, with the laser source providing a laser beam as an input to the collimator which provides an expanded and collimated optical beam. The additional incidental optical elements can include a spatial filter and a shutter mounted interposed between the laser source and the collimator.

Abstract: A neural network processing element uses primarily optical components to model a biological neuron having both spatial and temporal dependence. The neural network processing element includes a switch-controlled laser source, a multiple holographic lens, a spatial/temporal light modulator, and a photodetector array. Laser beam control may be optical, electrical or acoustical, or a combination of these.

Abstract: Optical correlator technology is applied to optical computing in the form of an optical interconnect utilizing multiple Fourier transforms in a hologram-based design.

Abstract: An image enhanced optical correlator system providing for optical preprocessing of an input image prior to processing thereof in an optical correlator. The optical preprocessing is provided to enhance the image and/or image related characteristics such that the probability of detection of prescribed targets therein in the optical correlator is increased. In the system, an input image beam is split into orthogonally polarized image inputs, processed to enhance targets therein, and then the algebraic result (addition and/or subtraction) thereof is processed through an optical correlator. Techniques are used in the feedback systems to enhance the output plane correlation signal detection by an adjustment in phase, spatial frequency filtering and/or threshold setting optimization.

Abstract: This invention enables a laser beam, expanding from a pinhole aperture spatial filter, to be brought back on the optical axis of an optical system such as an optical correlator system and maintained there. The principle of operation is that photodetectors spaced in the outer region of the expanding beam detect a change in orientation of the incident laser beam, and the change is measured and an error signal is used to drive electrically controlled micrometers so as to restore and maintain alignment.

Abstract: A mounting fixture for an optical instrument, such as an optical correlator, providing for the precise mounting and positional adjustment therein of an element, such as a multiple holographic lens, at least along two transverse x and y axes, and also rotationally along .theta. in roll about the z axis, .gamma. in pitch about the x axis, and .beta. in yaw about the y axis. The mounting fixture enables the holographic lens plate in an optical correlator to be positionally adjusted and then fixed stably in the optical correlator.

Abstract: A system for calibrating the output correlation plane of an optical correlator for positional and nonlinearity information to determine the position of an input image in an input image plane of the optical correlator. The optical correlator operates on the principle of projecting the Fourier transform of an input image onto at least one matched filter having recorded thereon the Fourier transform hologram of an image of interest. The inverse Fourier transform of the correlated optical signal is then projected onto a detector to determine the correlation of the input image with the image of interest. A calibration image is positioned in the input image plane of the optical correlator, and includes a two dimensional array of substantially identical targets, with the precise location of each identical target in the input image plane being known. At least one matched filter is placed in the optical correlator, and has recorded thereon the Fourier transform hologram of the identical target.

Abstract: As multiple matched filter memories for optical correlators increase in size, their design, fabrication and alignment becomes increasingly complex and critical for proper operation of the optical correlator. The present invention places special alignment targets on the multiple matched filter memory to provide for proper alignment thereof to enable efficient correlator operation.

Abstract: A robotic vision, optical correlation system which optically compares an input image with optical information stored in a multiple array of matched filters to provide identification and aspect information about the input image. The input image is incident upon a spatial light modulator, and the input image spatially modulates a coherent beam of radiation. A multiple holographic lens has the spatially modulated radiation beam incident thereon, and performs a multiple number of Fourier transformations thereon to obtain an array of a multiple set of Fourier transforms of the spatially modulated radiation beam. The array of matched filters has the array of Fourier transforms incident thereon, and each matched filter comprises a Fourier transform hologram of an aspect view of an object of interest.

Abstract: A polychromatic optical correlator system, comprising one or more devices to generate simultaneously a plurality of signal beams at a plurality of wavelengths, a beam recombiner to direct the signal beams along an axis to form a multicomponent, multiwavelength beam comprised of those signal beams, at least one view exposed to the signal beams to spatially modulate each of the signal beams, and a matched filter plate having a plurality of matched filters stored therein. A multiple beam generating holographic lens is located in the path of the multicomponent, multiwavelength beam to deflect each of the component signal beams thereof onto the matched filter plate, with each of the signal beams being focused on a respective one of the matched filters of the matched filter plate.

Abstract: An alignment fixture for an optical instrument such as an optical correlator providing for the adjustment of the alignment of an element thereof, such as a matched filter or multiple matched filter or a multiple holographic lens, along at least two transverse x and y axes, and also rotationally .theta. in roll about a z axis perpendicular to the transverse x and y axes. The alignment fixture is constructed with a base plate which is designed to be mounted on a stabilized optical bench. The base plate is movable along the z axis for adjustment therealong, and includes a vertically extending frame member. An L-shaped lift angle plate is vertically movably and supported by the vertically extending frame member to provide for alignment adjustments along the y axis. The L-shaped lift angle plate movably mounts a rotational stage in a manner which provides for alignment adjustments along the horizontal x axis.