94 results about "Optical processor" patented technology

An optical processor for controlling a phased antenna array uses a frequency-shifted feedback cavity (FSFC), which includes a traveling-wave cavity. The FSFC incrementally delays and incrementally frequency shifts optical signals circulating in the traveling-wave cavity. Optical signals coupled out of the FSFC are separated by frequency, hence by delay, and processed to control either or both transmit and receive beam-forming operations. The FSFC provides a receiver with multiple receive signals which have incremental values of frequency. Each frequency corresponds to an incremental time sampling of optical signals input into the FSFC. Transmit signals coupled out of the FSFC have frequency and phase relationships that result in short time-domain pulses when combined. Controlling modulation and frequency of the transmit signals achieves carrier interference multiple access, a new type of spread-spectrum communications.

The present invention provides an optical filter assembly that reduces the phase and amplitude noise of a detection laser used to detect ultrasonic displacements. The filtered detection laser is directed to the surface of a remote target. Ultrasonic displacements at the surface scatter the filtered detection laser. Collection optics then gather phase modulated light scattered by the surface and direct the phase modulated light to an optical processor to produce a signal representative of the ultrasonic displacements with an improved SNR. Additional processors may determine the structure of the remote target.

An optical differential phase shift key (DPSK) receiver, a method of demodulating an optical DPSK modulated signal and an optical processor capable of operating as either a DPSK receiver or DPSK transmitter. In one embodiment, the DPSK receiver includes: (1) an optical waveguide and a delay line associated therewith configured to receive simultaneously an optical DPSK modulated signal, (2) a coupler having at least two inputs and at least four outputs, the at least two inputs configured to terminate the optical waveguide and the delay line, the delay line having a path length difference that delays the optical DPSK modulated signal by at least one timeslot relative to the optical waveguide and (3) photodetectors associated with the at least four outputs and configured to provide signals indicative of digital data contained in components of the optical DPSK modulated signal.

A beam control system and method: The inventive system includes, an arrangement for receiving a first beam of electromagnetic energy; measuring wavefront aberrations in the first beam with a wavefront sensor; and removing global tilt from the measured wavefront aberrations to provide higher order aberrations for beam control. In the illustrative embodiment, the invention uses a traditional (quad-cell) Shack-Hartmann wavefront sensor to measure wavefront aberrations. An adaptive optics processor electronically removes the global tilt (angular jitter) from this measurement leaving only the higher-order Zernike components. These higher-order aberrations are then applied to wavefront control elements, such as deformable mirrors or spatial light modulators that correct the tracker image and apply a conjugate distortion to the wavefront of the outgoing HEL beam. A track error (angular jitter) component is supplied by a separate fine track sensor. This jitter error is then applied by the adaptive optics processor to a fast steering mirror, which corrects jitter in the tracker image and applies a compensating distortion to the LOS of the HEL beam.

The present invention provides a simple means of demodulating optical signals, e.g. wideband M-ary orthogonal. The demodulator comprises an optical processor and a comparison module. The optical processor transforms M input optical signals into 2 log2(M) intermediary optical signals and the comparison module determines the logical representation of the input data based on log2(M) binary comparisons of the optical power of the intermediary signals. Example embodiments may be reconfigurable to receive optical signals using M-FSK, M-PPM, M-PolSK, and hybrid M-ary orthogonal modulation formats. Example embodiments also offer small size, weight and power consumption for both free-space and fiber optic environments as well as improved receiver sensitivity and reduced electron bandwidth requirements.

A multispectral imaging system (1) and method utilize an optical processor (3) for simultaneously comparing an input wavelength spectrum observed in a single spatial pixel in a scene image from a multispectral imager (2) with a plurality of template wavelength spectra to find a correlation. The optical processor exploits the three-dimensional attributes of optical correlation to perform massively parallel correlation processing by modulating (4) respective ones of a plurality of spectral bands of the input wavelength spectrum of an incident light beam (6) with modulating elements (5) to alter at least one property of the incident light beam by a value corresponding to the observed intensity of the input spectrum in the respective spectral band. In a disclosed embodiment, the modulated beam is expanded and transited through a spatial light modulator (7) having a two-dimensional array of modulating elements. Each row of the elements of the array alter the at least one property of the incident light by values corresponding to a particular template wavelength spectrum of a plurality of template wavelength spectra of the modulator. The values corresponding to each template spectrum are the conjugates of the representative values of the modulating elements of the template spectrum of the plurality of template spectra.

Fractional Fourier transform properties of lenses or other optical environments are applied to one or more positive-definite optical transfer functions at locations outside the Fourier plane to realize or closely approximate arbitrary non-positive-definite transfer functions varying in both amplitude and phase. Controllable filter elements can be employed to create controllable optical processors which may be used for image filtering and optical computations using complex-valued arithmetic for monochromatic, color, and wide-spectrum optical signals. Applications include integrated optics, optical computing systems, particle beam systems, radiation accelerators, astronomical observation systems, and controllable lens systems.

A method of redirecting light using an actuatable two-layer diffraction grating structure, the method having applications in wavelength-division multiplexed systems. An optical add / drop modulator (OADM) including an actuatable diffraction grating, for use with a wavelength-division multiplexed signal. An OADM having an optical source located off the main pathway to direct a optical carrier to be added onto the actuatable diffraction grating such that the carrier is diffracted into the main pathway. A detector to measure signal strength for use with an optical processor, the optical processor having an actuatable structure having gaps between the actuated portion of the structure. The detector detecting the portions of light diffracted by the gaps.

The invention discloses a single-pixel two-dimensional imaging system and method using light frequency domain random frequency mixing. The single-pixel two-dimensional imaging system and method are characterized in that a mode-locked laser is utilized to provide a pulse light source which is amplified through an erbium doped fiber amplifier; the amplified pulse light source enters a collimating mirror through a circulator, and then irradiates to images requiring to be collected through a reflector, a semi-cylindrical lens, a virtual image phase array, a reflective diffraction grating and a cylindrical mirror and is reflected; optical signals return to the circulator along the original path; mixing of the optical signals and the pseudo random sequence frequency is implemented in a programmable optical processor; photoelectric conversion is performed through a photoelectric detector, and then sampling is performed through a digital sampling oscilloscope; and the oscilloscope samples each pulse peak value, and utilizes a compressed sensing algorithm to reconstruct the image signal. The single-pixel two-dimensional imaging system using light frequency domain random frequency mixing utilizes the programmable optical processor to implement mixing of signals and random sequence in a frequency domain to avoid the complicated process that a Mach-Zehnder modulator is used to modulate the random sequence after broadening of the fiber, and then the random sequence is compressed through the fiber for mixing in the time domain, thus having the advantages of being simple and compact in structure, and being easy to integrate.

Fractional Fourier transform properties of lenses or other elements or optical environments are used to introduce one or more positive-definite optical transfer functions outside the Fourier plane so as to realize or closely approximate arbitrary non-positive-definite transfer functions. Designs can be straightforwardly obtained by methods of approximation. The invention provides for single and multiple channel controllable optical processors which may be used for image or other types of computation, including computation with complex-valued arithmetic, visual color, and wide-spectrum optical signals. The invention also provides for synthesis of Fractional Fourier transforms, extensions to non-Hermite basis functions, phase-shifting filter elements and non-quadratic graded-index materials (which do not naturally invoke the Fractional Fourier transform operation). Applications include integrated optics, optical computing systems, particle beam systems, radiation accelerators, astronomical observation methods, and controllable lens systems.

A method of redirecting light using an actuatable two-layer diffraction grating structure, the method having applications in wavelength-division multiplexed systems. An optical add / drop modulator (OADM) including an actuatable diffraction grating, for use with a wavelength-division multiplexed signal. An OADM having an optical source located off the main pathway to direct a optical carrier to be added onto the actuatable diffraction grating such that the carrier is diffracted into the main pathway. A detector to measure signal strength for use with an optical processor, the optical processor having an actuatable structure having gaps between the actuated portion of the structure. The detector detecting the portions of light diffracted by the gaps.

An optical processor adapted to emulate an artificial neural network (ANN) having a plurality of interconnected layers, each layer having one or more artificial neurons, the processor having a spatial light modulator (SLM) optically coupled, via an optical mask, to a photodetector array. In one embodiment, the SLM has a plurality of pixels, each pixel being configurable to emulate an output portion of a corresponding artificial neuron in a signal-sending ANN layer. The optical mask has a hologram that encodes the weights corresponding to interlayer connections in the ANN and spatially modulates the light transmitted by the SLM. The photodetectors of the array spatially resolve the interference pattern produced by the spatially modulated light, with each photodetector being configurable to emulate an input portion of a corresponding artificial neuron in a signal-receiving ANN layer.

A method and apparatus for enhancing the receiving and information identification functions of multiple access communications systems by employing one or more optical processors configured as a bank of 1-D correlators. The present invention is particularly useful in a DS / SS CDMA communications system, resulting in a multiuser CDMA system that approaches carrier to noise performance (C / N) as opposed to being limited by multiple access interference (MAI). The correlators are arranged in parallel to detect and / or demodulate the received signal, in conjunction with one or more complex algorithms to perform near-optimum multiuser detection, perform multipath combining and / or perform carrier Doppler compensation. An improved receiver in accordance with the present invention comprises means for receiving a plurality of signals transmitted through a communications channel; signal conversion means for converting the received signals into a form suitable for input to the multichannel correlator; a multichannel optical correlator for identifying the presence of particular waveforms and estimating the relative time delay or delays, carrier frequency offset from expected, RF amplitude and RF phase for each received spread spectrum waveform present in the received plurality of signals; a controller for determining and providing to the optical correlator the appropriate set of reference hypotheses; and one or more receiver algorithms depending on the exact receiver function to be performed.