USA As Represented by Secretary of the Navy

Richard P Bocker

Keith Bromley

Michael A Monahan

Mark E Lasher

Barry L Drake

Thomas B Henderson

Stanley R Clayton

Henry J Caulfield

Larry B Stotts

William J Miceli

Optical architectures are presented for performing fully parallel, carry-free computation with a trinary, modified signed-digit number representation to allow addition, subtraction and multiplication. Two different optical schemes involving position and polarization encoding enable the fabrication of modular trinary logic systems that accommodate trinary numbers of different magnitudes. The optical systems made up of redundant three-dimensional modules provide a designer with latitude to simultaneously carry out addition, subtraction or multiplication optically and with reduced complexity.

Optical arithmetic logic using the modified signed-digit redundant

Optical architectures are presented for performing fully parallel, carry-free computation with a trinary, modified signal-digit number representation to allow addition, subtraction and multiplication. Two different optical schemes involving position and polarization encoding enable the fabrication of modular trinary logic systems that accommodate trinary numbers of different magnitudes. The optical systems made up of redundant three-dimensional modules provide a designer with latitude to simultaneously carry out addition, subtraction or multiplication optically and with reduced complexity.

A digital multiplication by analog convolusion algorithm is extended by a brid combination of both floating and fixed-point arithmetic. An acousto-optical time-integrating architecture uses a binary representation of the hybrid combination of floating and fixed-point arithmetic. An array of full adders in conjunction with a photodetector array avoids generating mixed binary outputs that normally result when the digital multiplication by analog convolution algorithm is applied so as to eliminate the need for analog-to-digital converters otherwise needed to convert mixed binary to pure binary.

Optical floating-point matrix-vector multiplier

An apparatus and method provide for the electrooptic performing of matrix-matrix multiplication, computation of the cross-ambiguity function and calculation of triple correlations. A collimated light source is pulsed to illuminate a first matrix of optically encoded information. Since the first matrix functions in the transmissive mode the same pulsed light is deflected by a polarizing beam splitter to a second matrix of optically encoded information. This matrix, functioning in the reflective mode reflects the pulsed, collimated light back through the beam splitter onto a third matrix of optically encoded information. The third matrix is operated in the reflective mode and reflects the pulsed, collimated light back to the polarizing beam splitter and onto a two-dimensional photodetector array. The photodetector array adds the successively arithmetically processed encoded informations from the first, second and third matrices of information. The information of the first matrix is advanced across the light path from the pulsed, collimated light source and the encoded information from the second and third matrices are advanced across opposite faces of the polarizing beam splitter in a mutually orthogonally displacement with respect to one another. Optionally, the information in the first matrix can be advanced across the path of the pulsed collimated light at right angles to that described above to effect substantially the same mathematical operations called for above.

Advanced cube processor

A electrooptic systolic array architecture performs matrix-matrix multiplication using incoherent light. The incoherent light is collimated and passed through a polarizing beamsplitter and onto a pair of optically reflecting light valves. Each of the valves has a number of cells which are continuously being updated in a clocked sequence to vary their reflectivity in acc

Matrix-matrix multiplication using an electrooptical systolic/engagement

The improved electrooptic signal processing relies upon matrix-matrix multiplication using twos complement arithmetic. A source of pulse collimated light illuminates two two-dimension spatial light modulators that operate in a reflective mode through a polarizing beamsplitter. Each of the spatial light modulators has a matrix of optically encoded information of numbers in the twos complement binary representation so that a mixed binary representation of signals is generated within the two-dimensioned photodetector array. The mixed binary representation signals are decoded to a twos complement binary representation or a decimal representation to be useful for more conventional processing techniques. The twos complement arithmetic when incorporated with the electrooptic architecture provides for a convenient means for handling bipolar numbers, avoids the need for matrix partitioning when the matrices are real and offers a means to improve accuracy over conventional optical analog techniques.

Electrooptical matrix multiplication using the twos complement

An electro-optical system for performing the computation of the radar ambiguity function or other similar mathematical function using the parallel processing capability of optical systems including a photo-responsive, real-time programmable mask for storing a set of sample values {s.sub.p }. A light source is positioned to illuminate the mask and have its intensity modulated as a function of the sample values {s.sub.p }. The image from the programmable mask is transferred to a CCD photo-sensor array that is clocked in synchronism with the light pulse outputs of the light emitting diode to give rise to electro-optical products which are integrated in the CCD structure to yield the ambiguity or other similar mathematical function.

Incoherent optical ambiguity function generator

A complex spatial filter is provided by the combination of two dichroic ctal plates, one quarter waveplate, and two linear polarizers. The complex spatial filter consists of real and imaginary parts, both of which can have either a positive or negative sign and the structure is capable of eraseably recording varying degrees of absorbency which exhibit polarization discrimination in a desired format that can then be used to process the Fourier transform of a light beam containing desired information.

Complex photodichroic spatial filter

An electro-optical system for performing matrix-vector multiplication includes a mask having a plurality of elements of substantially equal resolution area disposed in a matrix of M rows and N columns, each element containing recorded discrete information as defined by its degree of opacity which is representative of a predetermined mathematical value in a known matrix. A light source is positioned to illuminate the mask and has its intensity modulated as a function of the sequential values in a N X 1, vector. A multiple photo-responsive array including M elements disposed in a column is positioned to receive the light energy transmitted by the illuminated mask and generates signals at each element commensurate with the instantaneous photo energy received at its position. A suitable means which is synchronously operative with the modulation of the intensity of the light source, sequentially develops cumulative signals corresponding to the signal information contained in each column of the mask, producing a matrix-vector multiplication result.

Electro-optical system for performing matrix-vector multiplication

A multi-channel optical correlation system employs a light source to illuminate a mask having a plurality of linearly disposed channels, each of which has recorded information defined by variations in opacity along its linear length. The light source is modulated as a function of an unknown input signal. A multiple element charge coupled device having its elements arrayed in linearly disposed groups along axes parallel to the linearly disposed channels of the illuminated mask is positioned to receive the light energy transmitted by the illuminated mask for developing a charge within each such element commensurate with the photo energy received at its discrete position. A source of clock signals is periodically applied to the charge coupled device for cumulatively shifting the charges developed by each of the linearly disposed groups of discrete elements and a suitable means responsive to the resultant cumulative charge outputs of such groups indicates the group having maximum amplitude of cumulative charge thereby identifying the unknown input signal with the recorded information contained on the particular channel associated with that group.

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San Diego, CA, United States of America

Richard P Bocker