Abstract: An optical arithmetic comparator (OAC) is disclosed which is capable of comparing multiple numbers simultaneously, and indicating the common value of the multiple numbers being compared if the numbers are equal. The OAC includes at least two input channels each having a plurality of sources arranged in an identical pattern, the sources being capable of selective activation such that only one source is activated at a time within each of the channels to form a specific spatial light pattern, and a detector array which determines if the specific spatial light pattern indicated the numbers being compared are equal.

Abstract: An optical arithmetic comparator (OAC) is disclosed which is capable of comparing multiple numbers simultaneously, and indicating the common value of the multiple numbers being compared if the numbers are equal. The OAC includes at least two input channels each having a plurality of sources arranged in an identical pattern, the sources being capable of selective activation such that only one source is activated at a time within each of the channels to form a specific spatial light pattern, and a detector array which determines if the specific spatial light pattern indicated the numbers being compared are equal.

Abstract: A residue number system multiplication overflow detection processor generates either a VALID signal or an INVALID signal indicating whether multiplication overflow has occurred. Operands X and Y are received in residue representation and are multiplied in a multiplier. The X and Y operands are also converted to mixed base representation. The mixed base representations of the operands are compared in order to generate magnitude measures indicative of the magnitude of each of the operands. These magnitude measures and a mixed base representation of the product are used to generate the VALID and INVALID signals. The invention is particularly well-suited to be implemented using optical technologies.

Abstract: An encryption and decryption system performs encryption and decryption using the residue number system. A binary input signal is converted into residue number system representation in a binary to residue converter. Pseudo random numbers, generated from pseudo random number generators, are then added to the converted input signal in modular, that is, residue number system, adders. The outputs of the modular adders are converted into binary or mixed radix digit representation and are then transmitted to the location of a decrypter. The transmitted binary or mixed radix digit signal is converted back into residue number system representation in another converter and is then decrypted by subtracting the pseudo random number sequence. This decrypted signal is then converted into binary representation. The binary representation of the decrypted signal resembles the input signal.

Abstract: A residue addition overflow detection processor detects overflow resulting from the addition of two residue numbers by extending the base of the two numbers, adding the two extended numbers to each other, and converting the resultant sum into mixed base representation. The digits of the mixed base representation are processed to produce signals indicating whether overflow has occurred. Delay circuits maintain the synchronism of the processing. The detection processor can be used in conjunction with optical information processing systems.

Abstract: An optical computer arithmetic/logic unit using coherence multiplexing. A optical signal input into the device is distributed down two input channels. Each input channel contains different length optical fibers, or delay lines. To perform an operation, one delay line signal from each channel is selected. The two signals with their respective delays are multiplexed into output detectors which determine from optical interference the difference between the delay line lengths. The input from each channel coupled with the detected output can be set to perform residue arithmetic, or Boolean logic.

Abstract: An information processor receives a residue number as an input and generates a mixed base number correspopnding to the residue number and a redundant residue digit corresponding to the residue number. The information processor includes a plurality of optical arithmetic and logic units (OALUs) arranged in channels and stages. Each digit of the residue number corresponds to a channel. Each channel produces a mixed base digit associated with the residue input number. The stages are serially arranged to successively generate mixed base digits corresponding to the residue number by performing modular multiplication and modular subtraction. Delay circuits are arranged parallel to the plurality of OALUs such that all of the mixed base digits are transmitted from the information processor at the same time. An additional channel of OALUs calculates the redundant residue digit based on the mixed base digits.

Abstract: An optical computing system includes an input device, a converter and an optical computing device. The input device generates first light beams along selected ones of a first plurality of light transmitting paths. Each of the first light beams is representative of a digit of a number. The converter converts the first light beams into second light beams selected among a second plurality of light transmitting paths. Each of the second light beams is representative of the residue of the number modulo a given modulus among a plurality of mutually prime moduli. The converter generates, for each number, an ordered group of second light beams corresponding to an ordered group of residues modulo each of the mutually prime moduli. The optical computing device is coupled to receive the ordered group of second light beams from the converter for performing residue arithmetic operations.

Abstract: A technique for producing an integrated optics waveguide having a large index of refraction difference with respect to an otherwise similar waveguide that does not utilize the invention. A proton exchange region is formed in a lithium niobate substrate, and a titanium waveguide is formed in the substrate within the proton exchange region. The dimensions of the waveguide and proton exchange region are selected such that substantially all of the field of the lowest guided mode of the waveguide is contained within the proton exchange region. By utilizing such a waveguide as one arm of an interferometer formed in the substrate, a large optical path length difference between the interferometer arms may be created.

Abstract: Difference images, derived from an X-ray image of an anatomical subject, are produced in real time by directing X-rays through an anatomical subject to produce an X-ray image, converting the X-ray image into a series of television fields comprising trains of analog video signals, converting the analog video signals into corresponding digital video signals, integrating the digital video signals over a series of successive time intervals corresponding with a plurality of television fields and thereby producing a series of sets of integrated digital video signals, performing a series of subtractions between each set of integrated video signals and the preceding set of integrated video signals and thereby producing a series of successive digital difference video signals, converting the digital difference video signals into analog difference video signals, and converting the analog difference video signals into a series of visible television difference images representing changes in the X-ray image between the suc