Abstract: A multi-channel receiver which exploites the parallel processing advantages of an optical signal processor is used to facilitate 100 percent intercept of an incomming RF signal in a dense RF environment. The receiver performs real time parallel signal processing to effectively capture a given signal of interest. The receiver modulates a laser beam with incoming RF signals. The modulated laser beam is then Fourier transformed, channelized into an array of signals of varying frequencies, optically filtered and then down converted into their original radio frequencies with only the pass characteristics altered so that the captured signal can be readily identified. An electronic controller is used to control the pass structure of the optical filter which can be reconfigured in real time to selectively pass signals having the desired characteristics.

Abstract: A computer controlled optical system for angular alignment of structures which uses an optical imaging system input to a computer to synthesize regularly spaced reference and test line patterns replicated from binarized edges taken from the optical images of structures to be aligned. The two patterns are then combined resulting in an interference pattern in which the spacing of moire fringes indicates the amount of movement of the structures required to bring them to a predetermined alignment. All of the procedures are observable on the interference display. These moire fringe pattern are a quantitative measure of angular alignment between the reference and test images and of the edges from the structures from which they were taken. An operator programmed and controlled template automatically processes moire edge alignment measurements. An automatic template processor generates a test sequence template from the chosen areas for measurement by the operator.

Abstract: This invention uses an optical imaging system input to a computer to synthesize regularly spaced reference and test line patterns replicated from binarized edges taken from the optical images of structures to be aligned. The two patterns are then combined resulting in an interference pattern in which the spacing of moire fringes indicates the amount of movement of the structures required to bring them to a predetermined alignment. All of the procedures are observable on the interference display. These moire fringe pattern are a quantitative measure of angular alignment between the reference and test images and of the edges from the structures from which they were taken. An operator programmed and controlled template automatically processes moire edge alignment measurements.An automatic template processor generates a test sequence template from the chosen areas for measurement by the operator.

Abstract: A method and system for fabricating a multiple holographic element. The method comprises the steps of forming a master multiple holographic element having an absorption grating pattern that produces a given index of refraction pattern across the master multiple holographic element, coating the master holographic element with a layer of a photopolymer, and directing a recording beam to and through the master holographic element and into the photopolymer layer. The absorption grating pattern of the master holographic element modulates the amplitude of the recording beam, and the modulated recording beam causes the monomers of the photopolymer to form a monomer pattern that produces the given index of refraction pattern across the photopolymer layer. The method further comprises the steps of fixing the monomers of the photopolymer layer in that monomer pattern to form thereby a copy of the multiple holographic element, and removing the photopolymer layer from the master holographic element.

Abstract: A method and system for fabricating a multiple holographic element. The method comprises the steps of forming a master multiple holographic element having an absorption grating pattern that produces a given index of refraction pattern across the master multiple holographic element, coating the master holographic element with a layer of a photopolymer, and directing a recording beam to and through the master holographic element and into the photopolymer layer. The absorption grating pattern of the master holographic element modulates the amplitude of the recording beam, and the modulated recording beam causes the monomers of the photopolymer to form a monomer pattern that produces the given index of refraction pattern across the photopolymer layer. The method further comprises the steps of fixing the monomers of the photopolymer layer in that monomer pattern to form thereby a copy of the multiple holographic element, and removing the photopolymer layer from the master holographic element.

Abstract: A process and apparatus for measuring angular distortion in an optical imaging system in order to provide a mapping that completely characterizes the distortion of the imaging system involves electronically capturing the image of a test pattern at the image plane of the imaging system, superposing a computer generated reference pattern on the test pattern, and measuring the deviation of the test pattern from the reference pattern at selected areas of the reference pattern.

Abstract: A system for identifying and determining the orientation and location of multiple objects includes a camera and a mechanism for permitting the camera to scan a scene containing the objects. Objects in the moving scene are identified by optical filtering. Filters representing each of the objects to be identified are stored in a digital image memory, from which they are retrieved as needed, Fourier transformed, and loaded into a spatial light modulator to form a matched filter for an input image modulated and transformed laser beam.

Abstract: A coordinate measuring machine is described including a vertical probe shaft mounted on an X-axis carriage in turn mounted on a Y-axis carriage for movement along three orthogonal axes, in which the Y-axis carriage is guided and supported on a first guide beam fixed extending along one side of a machine base with air bearings mounted to the lower end of one upright engaging all four sides of the first guide beam. The Y-axis carriage is also supported on a second guide beam fixed extending along the other side of the base, with air bearings mounted to the lower end of the other upright engaging only the top and bottom surfaces. A lower crossmember beam connects the lower ends of the upright to increase stiffness of the Y-axis carriage. A cast aluminum table is supported on the base with three cast in support features projecting from the underside, configured to minimize thermal distortion, with a steel plate bonded into a recess in the upper surface.

Abstract: A photo stimulated and controlled imaging neural network for providing self generating learning sets and associative memory and programmability. An image to be recognized or detected is transferred to an imaging plane, which can be as simple as a lens or as complicated as a cathode ray tube. The imaging plane whose contents forms the input for a photo receptor array transfers the stimulus from the object to the photoreceptor array. The photoreceptor array responds to the stimulus provided by the imaging plane with various couplings between an array of neuron amplifiers. The photo receptor array comprises a plurality of synaptic photo controlled resistors which respond to the stimulus provided by the imaging plane. The individual neuron amplifiers settle into a set of on or off binary states based on the couplings of the photo controlled resistors which comprise the receptor array.

Abstract: A multiple target correlation system for unambiguously detecting, locating and determining the orientation of an array of multiple targets or objects. The multiple target correlator provides a means for fabricating a matched filter array or multiple matched filter with multiple targets stored on a single plate and a method for interrogating this multiple target matched filter with multiple scene images thereby providing for the identification of each object or target and determining its location and orientation in coordinates that are user selectable. The multiple target correlator utilizes a multiple matched filter having two matched filters for each particular object or target stored thereon, and each matched filter is positioned at a unique angle.

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: A method for generating holographic optical elements such as power spectrum filters is carried out using a printer and a computer. A signal function is input into the computer and traced by the printer to produce a power spectrum envelope of the signal function. The power spectrum is then filled in with a grating pattern whose line spacing is determined by the desired diffraction of coherent radiation beams used to interrogate the optical element.

Abstract: An optical notching filter is disclosed in which an optical spatial filter therein is formed by a spatial light modulator which is written into by light. The optical notching filter system of the present invention provides a linear phase and amplitude response with applications for high speed adaptive filtering to filter out noise and signals of no interest. In one particular disclosed embodiment, the write with light optical notching filter system of the present invention is designed to adaptively excise interference from Radio Frequency (RF) signals, such as are utilized in communications or radar systems. The technical approach of the present invention provides a more compact system design than similar electronically addressed optical notching filtering systems, and also significantly reduces the complexity and attendant power requirements of the system. Different embodiments of a write with light optical notching filter system can operate with either nonochromatic or polychromatic light sources.

Abstract: A system and method is presented for obtaining optical phase and amplitude measurements utilizing an acousto-optical modulator for modulating a laser light beam with a multifrequency electrical signal to form an image that is Fourier transformed and spatially distributed proportional to the frequency components of the electrical signal. An optical component such as a spatial light modulator is located in the Fourier plane and the modulated image is inversely transformed and optically heterodyned to produce a transformed image. The transformed image impinges a photodetector that produces an electrical output signal that is inputted to a network analyzer to measure phase and amplitude of the transformed image. The electrical output signal is compared with a reference signal and deviations from the reference signal provide a quantitative measurement of the phase and amplitude response of the spatial light modulator.

Abstract: A multi-channel filter which exploits the parallel processing advantages of an optical signal processor is used to sort, classify and remove noise or unwanted signals from signals of interest. This filter shall perform real time parallel signal processing to effectively channelize and remove unwanted spectra from the various signals of interest in a dense radio frequency environment. This would in effect transform a single channel that is corrupted with unwanted signals, interference and noise, to a number of discrete channels which are spectrally tailored to selected signals of interest. The filtering process is accomplished by modulating a laser carrier with the given signal of interest and performing all filtering functions optically and then down converting the filtered signal back into its original radio frequency for further use.

Abstract: Adverse environmental effects may be canceled from an optical processor which adjusts the phase of spatially distributed frequency components. This is achieved by projecting the optical modulated signal and a local oscillator optical signal along the same optical path and through the same optical components. Multichannel operation is achieved by positioning the optical components for each stage along a common axis.

Abstract: A method and apparatus for real time SAR recording and processing includes a first movable recording medium in the form of a rotatable disc having reusable and erasable photosensitive materials thereon to record SAR returns in the form of radial traces. The first recording medium is rotated to move successively through a write zone where the SAR returns are recorded and a read zone where the recorded SAR returns are optically processed to produce a SAR image. The SAR image is recorded on a second rotatable recording medium having reusable and erasable photosensitive materials. The second rotatable recording medium moves successively through a record zone where the SAR image is recorded in a transfer zone where the SAR image is interfaced with a further optical processing system such as an optical correlator.

Abstract: A tracking receiver is disclosed which utilizes optical processing for detecting and tracking input broadband chirp like emission signals. The tracking receiver includes a scanning local oscillator, the output signal of which is caused to be scanned in frequency. A mixer mixes the unknown input signal and the local oscillator output signal to produce an intermediate frequency (IF), frequency difference signal. The IF signal is analyzed in an optical spectrum analyzer which includes an acoustooptical modulator for modulating a beam of radiation, as a laser beam, with the intermediate frequency signal, and optical means, as a lens, for producing a spatial frequency distribution of the intermediate frequency spectrum in a Fourier plane. A photodetector array is provided in the Fourier plane for detecting the spatial spectrum.

Abstract: The invention features an optical spread spectrum decoder wherein linear, non-linear, and discontinuous broadband RF signals can be optically decoded.The system introduces a weighting function into a local oscillator beam, which is then combined with a laser beam which has been modulated with the RF signal, processed to remove unwanted spectral components and then compressed. The combined beams are then down-converted to recover the RF signal.

Abstract: A bridge type coordinate measuring machine characterized by a bridge (20) that has a closed loop configuration encircling the measuring machine base (10). The bridge (20) includes two uprights (21, 22), an upper member (23) connecting the uprights together and at least one lower member (24) connecting the uprights together below the upper surface (11) of the base (10). Bearings (41) for the bridge are offset inwardly from the vertical axes of the uprights of the bridge and a guideway (12, 13), along which the bearings travel, is located on each side of the base. The bearings (41) operate upwardly, downwardly and sidewardly against the surfaces of the guideways (12, 13) located on the sides of the base (10). This arrangement both stiffens and raises the resonant frequency of the bridge, thereby improving the measuring accuracy and repeatability of the coordinate measuring machines performance.