Abstract: An outer product shearing interferometer for an optical source of one-dimensional extent which provides simultaneous interference between every two points on the source. The interferometer comprises an input plane containing the source, an output plane for observing the outer product, an imaging system between the two planes, and a mask positioned in the transform plane of the imaging system and having slits arranged to effect the desired outer product. The desired outer product results from a simultaneous application of many lateral shears instead of only one at a time.

Abstract: A reprogrammable logic array is characterized by the use of a RAM fuse to selectively control the transfer of variable from input lines to intersecting output combination lines of the array. The configuration of the combiner array is programmed by writing to all of the RAM locations that are associated with the array. If a connection is to be made, a logical "1" is written to the RAM cell for that connection and if no connection is desired, a "0" is written to the RAM cell. The array which includes a novel input interface, can be quickly and easily reprogrammed simply by writing to the appropriate RAM cells. The RAM fuses may function as standard static RAM if the device does not need to function as a combiner.

Abstract: An improved asymmetric crystal topography x-ray imaging system employing a ine focus horizontal line source of x-rays and a crystal monochromator used in a compression mode. Relatively large horizontal and vertical dimensions of the monochromating crystal allow imaging of larger areas of imperfect crystals than previously possible, without adversely affecting image resolution. The high resolution two-dimensional images are a direct consequence of our method of controlling the probe beam divergences. An appreciably enhanced and useful intensity of monochromatic x-rays is obtained over that available with prior asymmetric crystal topography systems.

Abstract: An intrusion detection optical communication system modifies the original data signal to include a synchronizing periodic waveform. The receiver generates an inverted synchronizing periodic waveform signal corresponding with the transmitted signal to null the same under normal operation. When an intrusion in the optical system arises, power is extracted from the system and the nulled condition is disrupted. The disruption is detected and activates an alarm circuit when the disruption is above a threshold value.

Abstract: The reconfigurable pipelined processor includes a plurality of memory devices and arithmetic units interconnected by cross bars for transferring raw and processed data therebetween. A counter is connected with the cross bar to provide a source of addresses for the memory devices. At least one variable tick delay device is connected with each memory and arithmetic unit to variably control the input and output operations thereof to selectively delay the memory devices and arithmetic units to align the data for processing in a selected sequence.

Abstract: An improved tamper indicating seal is disclosed, characterized by the generation of a unique signature pattern which, if altered, is indicative of tampering. The seal includes a layer of transparent material which is applied to at least a portion of a secure object or container. A plurality of particles of refective material are randomly arranged within the layer in a unique orientation. When the seal is exposed to light, the particles reflect a portion of the light to produce a unique reflective pattern which corresponds with the orientation of the particles. Alteration of the particle orientation as a result of tampering alters the reflective pattern. Thus when the reflected pattern of a seal does not correspond with its original signature pattern, tampering is indicated.

Abstract: An optically controlled laser device is used to perform digital logic functions. The device comprises a single mode semiconductor laser including a waveguide for coupling light into the lasing caving at an angle at or near normal incidence with respect to the laser radiation generated by the laser. The single mode properties of the laser are achieved by index guiding. The coupled light interacts with the laser radiation in a small region of the lasing cavity creating a perturbation that quenches the laser output, whereby input of the coupled light enables the laser device to perform logic functions.

Abstract: In the hybrid encoder for video signals described the picture elements of a video picture are arranged into equally large data blocks and each newly entered data block, is compared with a data block of the previous video picture by means of a subtractor (SR). The data blocks of the previous picture are stored in a picture store (BS). In order to maintain the transmission bit rates as small as possible, the data blocks are conventionally subjected to a transformation (for example, a Fourier transformation) (F) and a subsequent quantization (Q). For the required strong bit rate reduction a rough quantization is necessary, which leads to a strong quantization noise. To eliminate the quantization noise a blockwise adaptive low-pass filtering (T,FTI) is performed in two signal paths of the hybrid encoder. The quantizer (Q) may then have a refined design or it may be omitted altogether.

Abstract: An apparatus is described which performs real time spectrum analysis of large bandwidth radio frequency signals. The apparatus allows the simultaneous monitoring of all frequencies within the band of interest, and operates in the presence of multiple frequencies.

Abstract: A method for achieving tapered contact sidewalls by wet etching during fabrication of a semiconductor device is characterized by the addition of a second layer of undoped oxide to a bilayer sandwich deposited over the wafer of the device. The second layer of undoped oxide reduces the etch rate at the oxide/photoresist interface thereby providing gradual taper and improved metal step coverage. The reduced etch rate extends the utility of wet etching without changing etchant bath concentration or temperature.

Abstract: An apparatus is described which performs optical processing on electrical signals to calculate the triple product integral in a manner which accommodates high bandwidth signals, which processes were formerly possible only in mechanically unstable designs.

Abstract: An apparatus is described which performs acoustooptical signal processing functions with incoherent light, which procedures were formerly possible only with coherent light devices. Specific embodiments include an optical excisor, i.e., a programmable filter; a multichannel radiometer, i.e., an apparatus which estimates the power spectrum of a signal accompanied by noise; and an ambiguity processor, i.e., a time versus frequency cross correlator.

Abstract: Common path time and frequency domain optical adaptive linear predictors are disclosed, characterized by wide bandwidth operation for use in channel equalization, source redundancy removal, speech encoding, and other areas. The predictors are noninterferometric, avoiding the instability of such processors in the prior art.

Abstract: A pneumatic sweep generator for use as an audio source in tests near vocal frequency ranges. A horn, whose volume may be controlled by air pressure and whose tone may be controlled by air velocity, is connected to an air supply in a dual-circuit arrangement. Mechanical control devices, such as manual and pressure release valves, are located within the circuit to provide for tone and volume control. A reciprocating air cylinder continuously varies the air velocity within the horn to sweep the frequencies in an adjustable manner. Electromagnetic interference is totally eliminated by a complete absence of electrical devices in either the device or in necessary controls.

Abstract: A method is disclosed for eliminating group delay distortion resulting from filtering an information-carrying analog signal. The method allows an analog signal to be converted to digital form and back again with zero group delay distortion. The analog signal is first band or low pass filtered with a filter having a pass band substantially larger than that required to filter only the signal of interest. The filtered signal is then digitized at a rate appropriate to the filtered signal, digitally filtered to remove all but the signal of interest, and down sampled to the transmission rate. A substantially reversed process is described for reconverting the digital signal to analog form. The method is shown to be equally effective with a multiplexed signal.

Abstract: An electrooptic apparatus is disclosed for linear predictive adaptive filtering. The apparatus combines the desirable filtering effects of a correlation cancellation loop method of linear prediction with the parallelism and large bandwidth capabilities of optical processing.

Abstract: An information processor is described which is especially suitable for efficiently sorting large quantities of binary data. Data in a plurality of storage devices is fed to a plurality of compare-exchange modules and is then selectively passed back to the storage devices by means of multi-input switches. A programmable microprocessor controls passage of data through the various components in an iterative process.

Abstract: An apparatus for controllable propagation of magnetic domains, or bubbles, through an arrangement of closely spaced magnetic propagating elements arranged in an input stage, a strip-former stage, and a decoder stage. Binary logic circuitry results from selective control of bubble movement through alternate paths of elements, with at least one of said paths producing a domain strip extending the full height of the strip-former stage. The decoder stage includes a propagating element spaced apart from the strip-former stage a distance sufficient to prevent propagation of all domains in the strip-former stage except for the full-height strip. The asymmetric geometry of the strip former stage makes the full elongation of a bubble dependent upon which input provided the bubble.

Abstract: An improved method for serial transmission of binary data. Data words are conveyed over a communications path by means of four discrete signals. Bit value detection circuitry within the transmitter sequentially tests the untransmitted bits. Upon detection of only a single value in all of the untransmitted bits, the value being all ZEROs or all ONEs depending on the embodiment, an end of word signal is transmitted. In the receiver, a register is initialized to the predetermined single value state. Upon receipt of a signal representing the alternate state, the corresponding bit in the register is changed. Receipt of the end of word signal stops the process, at which time the register contains the word which was to be transmitted, thus accelerating the speed at which certain words may be transmitted.

Abstract: A hybrid space/time integrating optical ambiguity processor in which time-sequential segments of a spatially modulated optical signal are received in a two-dimensional optical modulator. The output of the optical modulator is periodically imaged along one axis and transformed along a perpendicular axis, and the result is detected for further use. Two embodiments of the two-dimensional optical modulator are described; one utilizing an electrical-to-optical transducer and one utilizing an optical-to-optical transducer.