Qinetiq Limited

Rebecca Anne Wilson

Meirion F Lewis

Andrew Charles Lewin

Brian Sinclair Lowans

Terence John Shepherd

Paul Richard Tapster

David Arthur Orchard

Gregor John McDonald

Martin James Cooper

Richard M Amos

Peter Sample

Jonathan Alexander Skoyles Pritchard

Charlotte Rachel Helen Bennett

Meirion Francis Lewis

Apparatus () is provided which is arranged to accept an input data stream. In some embodiments, the apparatus () comprises a sampler arranged to sample the input data stream to provide k samples thereof, wherein each of the samples is n bits long and a string selector arranged to select m binary strings n bits long from at least a chosen subset of all random binary strings of a predetermined length. The apparatus () may further comprise a logical operator arranged to perform a logical function for each of the k samples with each of the selected binary strings to provide a vector, a memory arranged to store a matrix of the vectors generated from k samples, and an address generator arranged to generate RAM address segments from the matrix. In embodiments, the apparatus () may comprise a processor for, for example, pattern matching; feature detection, image recognition.

Photonic processor with pattern matching and image recognition

This invention relates to a pattern recognition correlator in which a serial input data signal is converted into a parallel data signal for correlation with one or more reference data signals. The invention relates to use of a demultiplexer in such a correlation apparatus to reduce the data update rate for the subsequent components. The invention also relates to the use of a series of latch circuits to provide serial to parallel conversion of the input data signal in the electrical domain.

Correlation apparatus

This invention relates to a pattern recognition correlator and method for correlating input data with one or more reference data sets. The input data, which may be for instance digital amplitude modulated optical data, is used to modulate an optical signal to form a phase modulated optical signal. This temporal phase modulated optical signal is then converted into a parallel optical phase signal, preferably through use of an optical delay, and modulated by an optical phase modulator. When there is a correlation between the input data and the reference data the emerging wavefront is plane and can be strongly coupled to a detector. In the absence of correlation the emergent wavefront is not plane and so is not coupled as strongly to the detector. The detector output can therefore be used as an indication of correlation.

Optical correlation apparatus and method

An apparatus for detecting the presence of one or more images of a known kind in a scene is disclosed which comprises a digital input means and an optical output means. The digital input means comprises a capture means which passes a capture image to a first electronic processing means to produce a scene pattern corresponding to a Fourier Transform of the scene image. This pattern is then digitally combined with one or more reference patterns corresponding to Fourier Transforms of a reference image. The resulting combined patterns are then used to modulate a beam of light which may be focused to perform an inverse Fourier Transform providing correlation information. In a preferred embodiment, the combined pattern is displayed on a spatial light modulator. A 'smart' spatial light modulator is also disclosed which comprises an array of light modulating devices, each device comprising a detector and at least one pixel, whereby light incident upon the detector produces an output signal which is adapted to control the state of the modulating medium. By suitable processing, the 'smart' SLM may be adapted to either attenuate light below a certain intensity or only light above a certain intensity to act as a saturable absorber.

Method and apparatus for detecting the presence of one or more images of a known predetermined kind of scene

An optical phase detector comprising coupling means for receiving two optical inputs and for producing two combined optical outputs, means for detecting the two combined optical outputs and producing two corresponding electrical signals, and means for measuring the difference between the two electrical signals and generating an output difference signal which may be used to provide an indication of the phase difference between the two optical inputs. The optical phase detector comprises a voltage-tuneable electro-optic phase modulator for modulating the phase of an optical input to the optical phase detector to provide a linearized response. In this arrangement the output difference signal may be maintained at a constant level by varying the voltage applied to the electro-optic phase modulator, the applied voltage providing an indication of the phase difference between the two optical inputs. Applications include frequency discriminators, various sensors, and a laser stabilization apparatus.

Optical phase detector

A vertical cavity surface emitting laser (VCSEL) comprising a one dimensional grating structure configured to act as a waveguide, preferably located at an end surface of the VCSEL, for selectively reflecting more of a first polarisation of light back into the cavity of the VCSEL than a second orthogonal polarisation of light. Preferably the VCSEL comprises an upper Bragg mirror, a gain region, and a lower Bragg mirror, and the one dimensional grating structure is located on a top layer of the upper Bragg mirror and the top layer of the upper Bragg mirror has a thickness such that the reflected light of one polarisation constructively interferes with light of said one polarisation which is reflected by the upper Bragg mirror. The VCSEL will then lase at the polarisation which is more predominantly reflected by the grating structure.

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Malvern, United Kingdom

Rebecca Anne Wilson