Abstract: All-Optical logic can avoid expensive demultiplexing back to electronics in telecommunications. The term all-optical is used to described processing in which all signal paths are optical whether used for control or information. Semiconductor optical amplifiers (SOAs) can perform all optical logic because they have nonlinearity, low latency, and require low power. We use highly accurate computer models to simulate and evaluate NOR and NXOR logic gates using SOAs. These elements can act as building blocks for advanced logic systems. For example, in previous publications we described an approach to constructing arithmetic units form optical logic elements.

Abstract: A method and apparatus for performing logic operations using quantum polarization states of single photons, include a first polarizing beam splitter having first input spatial modes and first output spatial modes for a first set of orthogonal polarizations. A second polarizing beam splitter has a second input spatial mode and second output spatial modes for a second set of orthogonal polarizations. The second set of orthogonal polarizations is different from the first set. The second input spatial mode is aligned with a first detected output spatial mode. A single photon detector of multiple single photon detectors is disposed along each one of the second output spatial modes. A first device output carries an output photon based in part on a number of photons detected by the single photon detectors. Such logic operations may be used in quantum computers for quantum information processing.

Abstract: An optical sampler based on stable, non-absorbing optical hard limiters includes an optical feedback loop for storing an optical signal in optical form. The optical feedback loop includes appropriate components for amplifying/reproducing the stored optical signal. The optical sampler outputs the stored optical signal.

Abstract: An optical memory suitable for storing optical signals from a set of predetermined wavelengths is demonstrated. This memory is random access, allowing a controller to read the stored data at any point in time. The memory has a memory input port for receiving a first optical signal, an optical storage element for storing an optical signal and its predetermined wavelength. The optical storage element features a set of optical sources each having a predetermined wavelength and is for providing an intensity and a wavelength of light stored therein. The optical memory also has a memory output port which is optically coupled to the optical storage element for selectively providing an output signal based on the wavelength and intensity of the light within the optical storage element.

Abstract: An optical switching device based on stable, non-absorbing optical hard limiters optically switches optical information from an input to a number of outputs based upon address information contained in the optical information. The optical switching device optically detects the location of the address bits in the optical information, optically samples the address bits, optically decodes the sampled address bits, optically activates an output based upon the decoded address bits, and optically outputs the optical information over the activated output.

Abstract: A logic device for use with data signals having a continuously or semi-continuously varying waveform of substantially fixed frequency. The device provides a logical output from at least one of the data inputs and comprising a first pair of inputs each to receive a data signal having one of a predetermined set of values representing analog, discrete, or digital states. A combiner stage is used to combine the inputs and produce a signal therefrom. A filter stage is utilized to receive the signal and produce a conditioned signal representative of one of a pair of binary states. The conditioned signal is combined with a second control input. The resultant signal is passed to an output.

Abstract: The present invention relates to the all-optical logic AND operation in a SOA (semiconductor optical amplifier)-based Mach-Zehnder interferometer. More particularly, it relates to the technology making feasible ultra high-speed logic operations while maintaining a small size and a low input power by utilizing a cross-phase modulation (XPM) wavelength converter composed of semiconductor optical amplifiers in the form of a Mach-Zehnder interferometer with nonlinear characteristics.

Abstract: A logical element including an optical junction coupled to at least two optical inlets and to at least one optical outlet. Incoming light beams of coherent monochromatic light beams and the same uniform frequency are applied to the optical inlets, and their super-positioning is provided as an outgoing light beam(s) via the optical outlet to another logical element or to a light intensity gauge. The light intensity gauge measures light intensity in specific zone(s) of an interference pattern created by the outgoing light beam, dependent on phase shift difference between the components of the incoming light beams, and the measured intensity is correlated with intensity ranges predetermined to conjugate to logical integer values, such as Boolean or other integer numeric values. A multiplicity of logical elements can be installed to provide an optical processor. Parallel use of the same logical element is provided by the simultaneous application of sets of light beams.

Abstract: A method and apparatus for performing logic operations using quantum polarization states of single photons, include a first polarizing beam splitter having first input spatial modes and first output spatial modes for a first set of orthogonal polarizations. A second polarizing beam splitter has a second input spatial mode and second output spatial modes for a second set of orthogonal polarizations. The second set of orthogonal polarizations is different from the first set. The second input spatial mode is aligned with a first detected output spatial mode. A single photon detector of multiple single photon detectors is disposed along each one of the second output spatial modes. A first device output carries an output photon based in part on a number of photons detected by the single photon detectors. Such logic operations may be used in quantum computers for quantum information processing.

Abstract: An optical packet header processing apparatus for processing a header of an optical packet expressing an address of a destination node to control a switching operation of an optical packet switch. The optical packet header processing apparatus comprises a beam splitter for splitting the optical packet header into a predetermined number of optical packet header elements, and a plurality of time interval detectors. Each of the time interval detectors receives a corresponding one of the optical packet header elements from the beam splitter and outputs a detect optical pulse if a pair of optical pulses having a predetermined time interval therebetween are present in the received optical packet header element. A plurality of optical pulse detectors are adapted to convert the detect optical pulses from the time interval detectors into electrical signals and transfer the converted electrical signals to the optical packet switch, respectively.

Abstract: An optical control apparatus having an optical reflector for selectively reflecting signal light having a specific wavelength, transmitting and outputting signal light having another wavelength and a saturable absorber for transmitting and outputting the transmitted signal light when an output level of the transmitted signal light is equal to or larger than a predetermined threshold value.

Abstract: The present invention relates to a routing address encoder, a routing controller, and a routing switch, which decrease the number and the length of optical splitting and optical delay line at optical routing circuits in optical communication network. A routing address encoder in accordance with an embodiment of the present invention includes a pulse generator, an external modulator, an optical address generator, an address selection signal generator, an optical switch, and optical OR gate means. An optical routing circuit for decoding optical routing information received from optical communication network and routing optical signals on the basis of routing address is provided. An optical routing circuit includes an optical splitter, a routing controller, and a routing switch.

Abstract: A coupler-based programmable phase logic device operates using coherent optical or microwave signals. The device is composed of a mixing stage and a logic stage and utilizes 3-port and 4-port couplers, such as integrated optic non-3dB Y-branches and integrated optic directional couplers. The device receives two coherent data input signals and three coherent control input signals and produces a coherent phase modulated data output signal. The data input signals are externally phase modulated to have one of two relative phase values, as in the binary phase shift keying (BPSK) method The data output signal is a phase modulated signal having one of the two relative phase values that is related to the phase values of the data input signals by a Boolean logic function, such as OR, AND, NAND, or NOR. The control input signals determine the logic function performed by the device and can be changed dynamically for dynamic device operation.

Abstract: Various optical logic devices are formed using stable, non-absorbing optical hard limiters. These optical logic devices are able to process information optically without the need to convert the information to an electronic form for processing electronically.

Abstract: There are disclosed molecular scale devices for performing logic functions. Devices comprise at least one input molecular unit, at least one output molecular unit, at least one molecular unit for performing logic or memory functions, and a means for effecting charge transport. Devices of the invention are useful for a variety of electronic and optoelectronic applications.

Abstract: A novel semiconductor optical amplifier (SOA) can operate as an optical inverter as well as a power-restoring device. Together, an optical-OR and the optical inverter can provide a wide variety of high speed optical logic gates and functions. The optical inverter uses cross-gain modulation (XGM) to invert a modulated signal on a first input, to produce an inverted output. The inverse of the modulation is transferred from a first wavelength of the modulated first input to a second wavelength of a continuous-wave second input. A filter can then block the first wavelength, allowing the inversely-modulated second wavelength to be output as the inverted output. The first and second wavelengths are swapped in alternate inverters in a logic path. The Y-junction can be implemented as a Multi-Mode Interference (MMI) device.

Abstract: An optical logic device comprises a dielectric block arranged such that a driving light is incident on one plane thereof at a total reflection critical angle through an interior thereof, a metallic film formed over the one plane of the dielectric block, and an optical functional film, a refractive index of which is changed by irradiation of light, formed over the metallic film such that the optical functional film is irradiated with a control light. A surface plasmon device is fabricated, which comprises a dielectric block arranged such that a driving light having a uniform intensity is incident on one plane thereof at a total reflection critical angle through an interior thereof, a metallic film formed over the one plane of the dielectric block, an optical functional film, a refractive index of which is changed by irradiation of light, formed over the metallic film such that the optical functional film is irradiated with a signal light subjected to space modulation.

Abstract: An optical switching device based on stable, non-absorbing optical hard limiters optically switches optical information from an input to a number of outputs based upon address information contained in the optical information. The optical switching device optically detects the location of the address bits in the optical information, optically samples the address bits, optically decodes the sampled address bits, optically activates an output based upon the decoded address bits, and optically outputs the optical information over the activated output.

Abstract: An optical sampler based on stable, non-absorbing optical hard limiters includes an optical feedback loop for storing an optical signal in optical form. The optical feedback loop includes appropriate components for amplifying/reproducing the stored optical signal. The optical sampler outputs the stored optical signal.

Abstract: An apparatus and method for realizing an all-optical NOR logic device includes a distributed feedback laser diode and a tunable laser diode respectively generating two pump signals of different wavelengths. The apparatus also includes a pulse generator and a Mach-Zehnder modulator modulating the pump signals. The apparatus also includes a delay line adapted to delay a pump signal that has been split from the modulated pump signals and that travels along one optical path, and a polarization controller and an optical attenuator adapted to control another pump signal that has been split from the modulated pump signals and that travels along another optical path, to have the same polarization and intensity as those of the pump signal passing through the delay line. An Er-doped amplifier amplifies the sum of the pump signals so that the amplified pump signal sum saturates a semiconductor optical amplifier.

Abstract: Logic operations are carried out among multiple optical signals based on their wavelength. The logic operations can be based on four wave mixing which produces an output based on polarizations of the inputs. The same circuit can be caused to carry out multiple truth tables. Applications are disclosed for adding, logical inversion, and error correction. The error correction can take the form of parity bit generation or correction of data bits.

Abstract: If a quantum mechanical state including a plurality of two-level systems (x1, x2, . . . , x2p+1) is expressed by a superposition of orthonormal bases in which each two-level system assumes a basic or an excited state, a quantum gate network is used to perform an operation including a combination of a selective rotation operation and an inversion about average operation D in order to configure a desired partly-entangled quantum mechanical state in which the coefficients of the respective bases are all real numbers.

Abstract: A device (1) for converting an RZ signal into a NRZ signal comprising:

Abstract: A determination is made as to whether sequential binary bits modulating optical energy have a certain bit pattern by applying the energy to an optical line having plural points from which optical energy is derived. The propagation speed of the optical energy in the line, the duration of the bits and the locations of the points are such that each of the binary bits passes by each of the points for approximately the same time, the propagation time of the energy between adjacent points equals the duration of each bit and the bits at the points are substantial replicas of the sequential binary bits modulating the optical energy. The values of the bits at the points are compared with the certain bit pattern to provide the determination.

Abstract: An architecture for optical logic gates is presented in which N predetermined wavelengths of light are used to define data. This data is manipulated by N-valued optical logic gates based on a set of rules referred to as Song's switching algebra. The gates when connected end to end to produce optical circuits such as optical random access memory or an optical arithmetic logic unit.

Abstract: An optical switch with simple circuit structure and increased a response speed is disclosed. This optical switch comprises a light combiner for combining a light signal &lgr;S and a control light &lgr;C and outputting a combined signal, and a saturable absorption type optical device provided with an input port and an output port, and outputs a light signal based on the combined light signal outputted from the light combiner. When an input power of the light signal &lgr;S is at a region where a light signal applied to the saturation absorption type optical device is attenuated, the light intensity of the control signal &lgr;C is set to the OFF state, and when the input power of the light signal &lgr;S is at a region where a light signal applied to said saturation absorption type optical device transmits therethrough, the light intensity of said control signal &lgr;C is set to the ON state.

Abstract: An optical phase oscillator with a maximum output amplifier generates an oscillating phase signal and employs an amplifier that is operated at maximum output to maintain a constant magnitude oscillator output signal. A non-maximum output amplifier with a signal limiter can also be used. The device receives a continuous or semi-continuous wave input signal and produces an oscillating phase output signal that has the same wavelength as the input signal. The phase oscillator consists of a combiner, an amplifier, a phase inverter, and a splitter. The coherent input signal is used as an initialization signal to start the oscillations and does not need to remain on for steady-state operation. An inverted phase feedback signal advances the oscillations. The amplifier provides a signal large enough to be split into the output signal and a feedback signal.

Abstract: An optical device for processing a digital optical signal in parallel and in free space, the said device comprising:

Abstract: If a quantum mechanical state including a plurality of two-level systems (X1, X2, . . . , X2p+1) is expressed by a superposition of orthonormal bases in which each two-level system assumes a basic or an excited state, a quantum gate network is used to perform an operation including a combination of a selective rotation operation and an inversion about average operation D in order to configure a desired partly-entangled quantum mechanical state in which the coefficients of the respective bases are all real numbers.

Abstract: A device and method for quantifying the amount of jitter experienced by an optical data pulse. During transmission data pulses may suffer jitter. Their arrival time at a node may be temporally offset from its predicted arrival time. Data pulses are timed so that they may be received at a detector disposed downstream of said node at a predetermined time.

Abstract: An optical device is provided for processing a digital optical signal in parallel and in free space. A device consistent with the invention provides for inputting a digital optical signal in guided propagation, converting the digital optical signal to n digital optical signals in guided propagation, and converting the n digital optical signals to n digital optical signals in free space. In addition, the invention provides for selecting a bit preselected from the at least one temporal series of n bits of each of the n digital optical signals, modifying optically, at least one bit of the spatial figure of the n bits, and outputting the at least one bit of the spatial figure of n bits.

Abstract: Pattern-recognition computing can be accomplished using wave-type or other types of energy. In pattern-recognition computing which uses a plurality of wave-type energy input patterns modulated with quantized information, energy from the patterns combines to produce interference-based dynamic images. Component parts of a dynamic image are separated and recombined to produce logic and other computing process outputs. To produce a coordinated set of optics for pattern-recognition computing, waveforms at pixel-sized image components of the dynamic image are chosen to become contributors to the combined output if they will contribute (or can be modified to contribute) in a positive manner to a combined output waveform that obeys the logic rules of the device being produced. Iterative changes in input pattern characteristics are used to optimize the coordinated optics. Pattern-recognition computing can also use special interference and frequency-multiplexed logic.

Abstract: A method for all photonic computing, comprising the steps of: encoding a first optical/electro-optical element with a two dimensional mathematical function representing input data; illuminating the first optical/electro-optical element with a collimated beam of light; illuminating a second optical/electro-optical element with light from the first optical/electro-optical element, the second optical/electro-optical element having a characteristic response corresponding to an iterative algorithm useful for solving a partial differential equation; iteratively recirculating the signal through the second optical/electro-optical element with light from the second optical/electro-optical element for a predetermined number of iterations; and, after the predetermined number of iterations, optically and/or electro-optically collecting output data representing an iterative optical solution from the second optical/electro-optical element.

Abstract: An optical switch includes a saturable absorption type optical element provided with a saturable absorption region, and a band-block optical filter to which signal light composed of at least one wavelength light having an optical power in the absorption region of the saturable absorption type optical element and control light whose optical power is set such that a total power of the signal light and the control light comes within a transmission region of the saturable absorption type optical element and which is composed of either one of two wavelength lights different from that of the signal light are inputted and which transmits therethrough the signal light and the control light which is composed only of one of the wavelength lights and outputs the transmitted signal light and control light to the saturable absorption type-optical element. ON/OFF of the signal light is controlled by varying the wavelength of the control light.

Abstract: A programmable optical logic gate for performing a selected function from the group including ALWAYS, NEVER, and logical OR, AND, NAND, NOR, XNOR, and XOR includes an optical logic circuit for receiving a first optical operand signal and a second optical operand signal and for performing a logic function on the first and second operand signals to produce an output signal, and further includes an optical logic function selection circuit coupled to the logic circuit for receiving logic function control signals and for selecting a logic function performed by the logic circuit on the first and second optical operand signals.

Abstract: The invention features methods and systems for processing signals by optically manipulating polaritons. In one embodiment, the signal processing method includes: converting a plurality of spatially separated input signals into polaritons that propagate in a signal processing material; optically manipulating the polaritons at a plurality of spatially separated locations in the signal processing material; and converting the manipulated polaritons into at least one output signal. In another embodiment, the signal processing method includes: converting an input signals into a polariton that propagates in a non-conductive signal processing material; optically manipulating the polariton as it propagates in the signal processing material; and converting the manipulated polaritons into an electrical output signal at an interface between the signal processing material and a conductive path in another material.

Abstract: A packaged smart pixel array for a reconfigurable intelligent optical interconnect is described. The smart pixel array (298) comprises an optical-to-electronic optical I/O channel 68 input means, an electronic-to-optical optical I/O channel 68 output means, an electrical channel input means (134), an electrical channel output means (114), a data switching means (110) for switching data from optical channel input means to electrical channel output means, a data switching means (130) for switching data from electrical channel input means and optical channel input means to optical channel output means and a packaging means (300) which packages all these means onto a single package with identifiable input and output port means. The smart pixel array makes possible the realization of a reconfigurable optical interconnect which implements multiple reconfigurable optical communication channels.

Abstract: An optical logic device is provided by an interferometer having an output which defines a logic state 1 or 0 in dependence upon an interference condition existing in the interferometer. Each arm of the interferometer contains a semiconductor optical amplifier in which the effect of cross phase modulation is utilized to modulate the phase of light transmitted through the respective arms. Optical signals are counter propagated through one or both of the arms in order to provide the cross modulation and thereby enable the interference condition to be set to one or other of the logic states. Automatic level control is provided at inputs to the interferometer and between successive stages of logic device. The method has application to high frequency digital optical communication systems where all optical logic operations are required.

Abstract: An optical logic device is provided by an interferometer in which an output optical signal is determined in accordance with an interference condition of the interferometer. The interference condition is reset by an optical setting signal which is counter-propagated through a semi-conductor optical amplifier forming one arm of the interferometer. Latching of the interference condition in the set state is achieved by a feedback signal taken from the output optical signal and combined with the setting signal. Resetting of the interference condition is achieved by nulling the output optical signal by counter-propagating a reset optical signal via second semiconductor optical amplifier constituting the second arm of the interferometer. Alternatively the input optical signal to the interferometer may be interrupted to null the output. A further alternative arrangement utilizes an electrical re-setting signal which actuates an electrical phase shifting device in the second arm of the interferometer.

Abstract: A packet carried on an optical network is routed by carrying out a logic operation on an address word carried in a packet header and a predetermined discriminator word. A routing decision is made in accordance with the result of the logic operation. The logic operation may be a bit-wise Boolean AND operation. An additional logic operation may be carried out with an additional discriminator word to determine whether the packet is destined for a remote region of the network. In this case, the packet may be steered directly to the remote region.

Abstract: An optical computer includes a plurality of functional elements (thin-film elements) each adapted for causing an external signal to act on a two-dimensional-information incident light so as to perform information processing, and light sources for transferring the two-dimensional-information incident light between the functional elements. Each of the functional elements includes nanoparticles comprising molecules of an organic compound and associates/aggregates of these molecules. This structure makes it possible to input light beams from a plurality of functional elements to a single functional element and to output light beams from this single functional element to the plurality of functional elements.

Abstract: Pattern-recognition computing can be accomplished using wave-type or other types pf energy. In pattern-recognition computing which uses a plurality of wave-type energy input patterns modulated with quantized information, energy from the patterns combines to produce interference-based dynamic images. Component parts of a dynamic image are separated and recombined to produce logic and other computing process outputs. To produce a coordinated set of optics for pattern-recognition computing, waveforms at pixel-sized image components of the dynamic image are chosen to become contributors to the combined output if they will contribute (or can be modified to contribute) in a positive manner to a combined output waveform that obeys the logic rules of the device being produced. Iterative changes in input pattern characteristics are used to optimize the coordinated optics. Pattern-recognition computing can also use special interference and frequency-multiplexed logic.

Abstract: All-optical devices, e.g., optical switches and modulators, and logic gates such as optical AND and OR gates, that include photochromic materials having first and second stable states, such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, irradiated in a four-wave mixing geometry, are described. These devices can be used in a wide variety of systems, such as, e.g., optical signal processors and optical computers.

Abstract: Logic operations are carried out on binary optical signals using a non-linear optical amplifier having a front port and a rear port respectively receiving a front wave and a modulated rear wave. The output wave via the rear port is separated from the rear wave by exploiting the fact that they have opposite propagation directions. Applications include optical data switching and transmission.

Abstract: A means and method of controlling a plurality of energy beams with at least one of the plurality of beams. At least one first beam set produces special interference with at least one second beam set, at a first location(s), diverting energy from both beam sets to a second location(s), where energy does not appear from one . . . or either, of the inputs in the absence of interference. By selecting the timing, levels, phases, frequencies, and interconnection of multiple controllers, a multitude of useful energy beam circuits are able to be made . . . such as: gated amplifiers, cascaded amplifiers, gated oscillators, phase demodulators, active filters, inverters, inverted filters, limiters, threshold detectors . . .

Abstract: A means and method of controlling a plurality of energy beams with at least one of the plurality of beams. At least one first beam set produces special interference with at least one second beam set, at a first location(s), diverting energy from both beam sets to a second location(s), where energy does not appear from one . . . or either, of the inputs in the absence of interference. By selecting the timing, levels, phases, frequencies, and interconnection of multiple controllers, a multitude of useful energy beam circuits are able to be made . . . such as: gated amplifiers, cascaded amplifiers, gated oscillators, phase demodulators, active filters, inverters, inverted filters, limiters, threshold detectors . . .

Abstract: By using a ferroelectric liquid crystal light valve having a hydrogenated amorphous silicon photoconductive layer, a spatial light modulator may be driven by a method comprising the sequential application of successive pulse voltages of selective amplitude, polarity and duration to cause the spatial light modulator to manifest a second threshold level suitable for application of the device in Boolean processing applications and Fourier image processing.

Abstract: An optical code recognition unit (OCRU) for recognizing a predetermined n-bit optical code has an n-way splitter having an input and n parallel outputs. A plurality of combiners are associated with the splitter outputs, and a respective gate is controlled by the output of each of the combiners. Each of the splitter outputs is subject to a different delay of from 0 to (n-1) bit periods, and each combiner receives an input from at least one of the splitter outputs. The OCRU is such that all the gates are turned on if a predetermined optical code is applied to the splitter input.

Abstract: An optical digital holding apparatus of the present invention carries out functions of a flip-flop apparatus (RS flip-flop, D flip-flop etc.) which are one kind of electrical digital holding apparatus, and can be achieved by placing optical connecting wiring having a direct or indirect feedback circuit between multistage optical selectors having selector functions. The optical digital holding apparatus of the present invention includes multistage selectors which receive an aggregation of spatially distributed optical digital information signals propagating in a predetermined direction and bearing binary digital information and an optical control signal bearing binary digital information. These selectors selectively output a portion of an aggregation of the digital information signals received in accordance with a value of the digital information carried by the optical control signal.

Abstract: A means and method for performing frequency-multiplexed logic, amplification, and energy beam control functions on individual channels simultaneously within a single device by using a plurality of frequency-multiplexed inputs each having beam sets of matching channel frequencies and simultaneously producing a set of interference images, one for each channel, and separating energy from the images to produce a frequency-multiplexed output. The individual functions performed on individual channels are the result of constructive and destructive interference within each channel's image.