Abstract: A deformable mirror is disclosed having replaceable, electrically operable actuators for deforming the mirror's reflecting surface. A flexible retraction membrane is disposed between the actuators and the reflecting surface and the mirror's facesheet is bonded to the retraction membrane. The membrane provides constant contact between the facesheet and the mirror's actuators and provides a deflection load to mechanically drive the facesheet downward against the operation of the actuators, thus providing a mechanical force to deflect the mirror's reflecting surface when electrical signals are selectively removed from one or more of the mirror's actuators. The membrane contains a gradient stiffness in the vicinity of each actuator to tailor the deformation profile, to maintain circular symmetry and to minimize the curve fitting error in the vicinity of each actuator.

Abstract: A carrier for electronic components which generate heat during their operation, such as high power semiconductors, is disclosed. The carrier includes complementary ends which are designed to permit the second end of a first carrier to abut and overlap the first end of a second carrier to conserve space when more than one carrier is mounted on a substrate containing an electronic circuit. Preferably each end of each carrier has an aperture bored therethrough to allow the carrier to be mounted to the substrate with fasteners such as screws. The apertures are located so that the aperture in the second end of a first carrier aligns with the aperture in the first end of a second carrier to permit a first and a second carrier to be fastened to the substrate with a common fastener passing through the aligned apertures. Similarly, the aperture in the second end of a second carrier is positioned to align with an aperture in the first end of another carrier.

Abstract: A fluoroscopic image is processed digitally using a television camera operating at a frame rate of at least 30 frames per second viewing the image and providing an analog video output, a digitizer which digitizes the analog video output to provide digital information representative of the analog signal, a plurality of frame processors which carry out arithmetic and logical operations on the digital image information and are operable at the frame rate of the television camera coupled to the output of the digitizer, a 2-D filter operable at the frame rate of the television camera coupled to said frame processors, a converter and interface to convert digital image information processed in the frame processors and 2-D filter back into an analog signal and television display coupled to the output of the converter for displaying the processed signal.

Abstract: A method of mixing light from a signal source with light from a local oscillator for heterodyne or homodyne detection using differential detection techniques is described. In the method and apparatus of the invention, incoming light is matched to the polarization of the local oscillator no matter what the polarization of the incoming light is. A sequence of three polarization beamsplitters is utilized to achieve this match. The local oscillator signal and the incoming signal are incident on separate faces of a first polarization beamsplitter. Each is divided into two beams by that beamsplitter and paired with the orthogonally polarized component of the other, each signal/local oscillator pair exiting from one exit face of the first polarization beamsplitter. The second polarization beamsplitter resolves one of these pairs into sum and difference pairs of matched polarization which interfere and are detected by square law detectors, forming currents which are subtracted in a differential amplifier.

Abstract: A plurality of digital words representing picture elements are sequentially loaded into a readin register, which words are thereafter written in parallel into a random access memory via a write data register. The words are subsequently readout of the random access memory in parallel into a read data register and to a readout data register which thereafter sequentially transmits the words stored therein to an output circuit. The arrangement is such that each word may flow through the pipeline to be processed during a clock period of P ns; although the RAM response time is greater than P ns.

Abstract: A wavefront of light is focused upon a first shearing interferometer having a relatively large shear and small dynamic range and a relatively minor portion of the light is focused upon a second shearing interferometer having a relatively small shear but large dynamic range. Owing to the limited dynamic range of the first shearing interferometer a plurality of a plurality of virtual candidate measurements are manifest which are compared with the temporally and/or spatially averaged values of each measurement produced by the second shearing interferometer and the closest match is employed to obtain a highly accurate unambiguous reading of the wavefront slope measurements.

Abstract: A shearing interferometer produces a matrix of loops of wavefront phase difference vector signals derived from the interferogram indicative of wavefront slopes, where each loop corresponds to a sub-aperture portion of the wavefront under examination. Curl operators are applied to sum the vector signals in one direction about the loops to provide sums which are set equal adjacent loops are identified having such modified sums differing from each other by at least one integer, and in certain cases having modified sums of integers of opposite sign indicative of phase difference measurements greater than the dynamic range of the interferometer, and thus having error components therein. The phase difference values at the boundary of each of such particular identified adjacent loops are operated upon to set the modified sums to zero, to in turn eliminate the error components due to operation of the interferometer outside of the limited dynamic range.

Abstract: A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chiping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

Abstract: A frame processor for processing digitized image information includes a memory for storing a two-dimensional array of pixels, logic circuits for controlling the writing and reading of information into the memory, an arithmetic and logic unit having two inputs, one of which is coupled to the output of the memory, and a microprocessor for controlling operation of the arithmetic and logic unit and the logic circuits for controlling reading and writing.

Abstract: A target is illuminated through an optically distorting region, such as atmospheric turbulence or non-precision optics, by coherent light and a first set of data is recorded indicative of the complex amplitude of scattered radiation and such target is thereafter illuminated by incoherent light to produce a second set of data indicative of the nature of the region; the second set is divided into the first set, and the resulting data is Fourier-transformed to produce a diffraction-limited target image.

Abstract: An infrared photodetector is disclosed which is deposited directly onto a Joule-Thomson cryostat. The cryostat includes an elongated body having gas-carrying channels contained therein. The photodetector is deposited directly onto one end of the elongated body to form a direct thermal path between the detector and cryostat, thereby eliminating the need for any intermediate thermal bridge such as a mechanical bond, thermal conductive paste or epoxy. The direct contact between the photodetector material and the cryostat reduces the thermal mass of the structure to be cooled by the cryostat, thereby decreasing both the time and the quantity of gas required to cool the detector.

Abstract: A fluoroscopic image is processed digitally using a television camera operating at a frame rate of at least 30 frames per second viewing the image and providing an analog video output, a digitizer which digitizes the analog video output to provide digital information representative of the analog signal, a plurality of frame processors which carry out arithmetic and logical operations on the digital image information and are operable at the frame rate of the television camera coupled to the output of the digitizer, a 2-D filter operable at the frame rate of the television camera coupled to said frame processors, a converter and interface to convert digital image information processed in the frame processors and 2-D filter back into an analog signal and television display coupled to the output of the converter for displaying the processed signal.

Abstract: A laser mirror having a cooled deformable reflecting surface is disclosed. The mirror's base includes a manifold for distributing coolant toward the mirror's faceplate and for receiving coolant which has circulated through the faceplate. The faceplate is comprised of a thin, deformable sheet of material which has a polished surface for reflecting laser radiation therefrom. The facesheet is supported above the base manifold by one or more actuators which may be selectively operated to selectively deform the mirror's reflecting surface. The faceplate includes one or more enclosed, elongated spaces which transverse substantially the entire width of the faceplate and through which coolant may be circulated to cool the faceplate. Coolant conducting members located around the periphery of the faceplate carry coolant between the faceplate and the base manifold to remove heat absorbed by the faceplate from the laser signal impinging on the mirror's reflecting surface.

Abstract: A cooled deformable mirror having a continuous mirror surface and a method for cooling a deformable mirror having a continuous mirror surface are disclosed. In the preferred embodiments, one or more enclosed spaces within the mirror's faceplate are supplied with coolant through one or more actuators used to deform the mirror surface and one or more other of the actuators are used to remove coolant from the mirror faceplate. The deformable mirror includes a base manifold which receives coolant from an external source and distributes the coolant to selected ones of the actuators for distribution within the faceplate. Coolant removed from the faceplate by others of the actuators is returned to the base manifold from which it is returned to the external source. Another preferred embodiment further includes a coolant distribution manifold in the faceplate to facilitate the distribution of coolant within the faceplate after the coolant has been delivered to the faceplate by the apertures in one or more actuators.

Abstract: A lightweight deformable mirror suitable for space applications is disclosed in which a plurality of electrically-operated electrodistortive actuators may be used to selectively deform the mirror's reflecting surface. The actuators are sandwiched between a pair of thin sheets of glass with the surface of one sheet finished to form the mirror's reflecting surface. By selectively energizing one or more of the actuators, the mirror surface can be deformed to correct aberrations in optical wavefronts impinging on the mirror or to encode signals into wavefronts projected onto the mirror surface. Electrical connections to the actuators may be made through printed circuit connections which are contained on the bottom sheet of the deformable mirror.

Abstract: A method of image motion distortion correction involving the steps of electronically scanning an optical image to produce first and second lines of stored digital pixel data indicative of the intensity of picture elements of the optical image, registering within a corresponding scanning window position the difference between each second line picture element value of a number of sets of second line picture elements, and a number of first individual line picture elements, each corresponding to an associated set, thereafter utilizing that particular window position having the minimum accumulated difference value to produce an image shift signal having a value corresponding to that particular window position, shifting the storage position of the second line with respect to the first line by an amount proportional to the value of the shift signal, and utilizing the shifted lines of data to modulate an image producing readout device such as a CRT to reproduce the optical image.

Abstract: Acousto-optical apparatus for determining the chip rate of a pseudo-random sequence of signals.

Abstract: An improved shearing interferometer is provided having an acousto-optic cell wherein two sets of orthogonal diffraction gratings are formed therein by applying two electrical signals thereto having different frequencies. A wavefront to be examined is passed through the cell, and both signal frequencies applied to the cell are varied to cause the resulting shearing interferogram to be sequentially directed at a pair of orthogonal linear photodetector arrays. The degree of shear may be readily adjusted by changing the difference between the frequencies of the two signals applied to the cell.

Abstract: An acoustic resonant structure for use in a tunable acousto-optic filter to reduce drive power requirements. The undesirable ripples in the tuning bandpass response due to acoustic resonance is minimized by reducing the effective finesse of the filter.

Abstract: A star pattern within the field of view is transmitted through a non-collinear acousto optic filter and is focused upon the input screen of a vidicon, which in turn is coupled to input storage devices of a computer, each device being associated with a particular frequency band within the spectrum of light being examined. The contents of the input storage devices are compared with binary data within a star catalog which contains geometric reference patterns of stars and their frequency signatures. When a correlation signal is produced by the comparator, an output signal indicating the position of the pattern in the sky may be produced by a dictionary which could form part of the computer or be remotely located with respect to the computer.