Abstract: Optical switches and logic devices comprising microstructure-doped nanocavity lasers are described. These switches and logic devices have gain and thus can be cascaded and integrated in a network or system such as for example on a chip. Exemplary switching elements switch the intensity, wavelength, or direction of the output. Exemplary logic devices include AND, OR, NAND, NOR, NOT, and XOR gates as well as flip-flops. Microfluidic sorting and delivery as well as optical tweezing and trapping may be employed to select and position a light emitter in a nanooptical cavity to form the nanolaser.

Abstract: A novel and efficient method for polarization conversion, particularly from linear polarization to circular polarization, and, importantly, vice versa, is obtained using shapeanisotropic self-assembled quantum dots, which, having the advantage of extremely small size (nanometer scale), may be readily incorporated into photonic crystals and/or other optical components. Such devices also have the advantage of working in the absence of an applied magnetic field. Such devices also, when a voltage bias is applied, can be used to manipulate electron spin by manipulating light polarization in the same circuit, and vice versa. This permits a high degree of control for either or both of these in spintronics and/or optical devices, the biased quantum dot being used as a nanometer scale electro-optic modulator. Components utilizing the method and/or devices may be used as part of highly compact optical computing networks and/or spintronics systems for e.g.

Abstract: Nonlinear elements can efficiently implement quantum information processing systems such as controlled phase shifters, non-absorbing detectors including parity detectors, quantum subspace projections, non-absorbing Bell state analyzers, non-absorbing encoders/entanglers, and fundamental quantum gates such as CNOT gates. The non-absorbing detectors permit improvements in the efficiency of a probabilistic quantum gate by permitting reuse of the same photonic resources during multiple passes through the probabilistic gate.

Abstract: Apparatus and methods of performing fast single-qubit quantum gates using ultrafast femtosecond frequency chirped laser pulses are disclosed. The use of chirped pulses removes the demanding restrictions of prior art approaches and allows for the construction of fast quantum gates that operate at speeds on the of order several picoseconds. The apparatus includes two synchronized lasers (pump and Stokes) used to manipulate a qubit wave function in a select manner. Each laser system generates a train of optical pulses. Pulse pickers choose pump and Stokes pulses, which propagate though respective pulse shapers that apply necessary time-dependent phases. To achieve complete overlap between the pulses in time domain, necessary adjustments can be made by using an additional time delay line, which can be located in any path or in both paths.

Abstract: An all-optical logic gates comprises a nonlinear element such as an optical resonator configured to receive optical input signals, at least one of which is amplitude-modulated to include data. The nonlinear element is configured in relation to the carrier frequency of the optical input signals to perform a logic operation based on the resonant frequency of the nonlinear element in relation to the carrier frequency. Based on the optical input signals, the nonlinear element generates an optical output signal having a binary logic level. A combining medium can be used to combine the optical input signals for discrimination by the nonlinear element to generate the optical output signal. Various embodiments include all-optical AND, NOT, NAND, NOR, OR, XOR, and XNOR gates and memory latch.

Abstract: An all-optical device for data processing is presented. The device comprises at least one optical waveguide unit (10) made of linear media and configured to provide multiple total internal reflections of light passing therethrough, the waveguide unit (10) comprising a waveguide portion (11) for interaction between reflected light components of input light; an input aperture arrangement (14) formed by at least one input aperture at an input facet of the waveguide portion (11); and an output aperture arrangement forme by at least one output aperture at an output facet of the waveguide portion.

Abstract: An optical logic gate (10) comprising inputs (12) for optical signals on which to perform a chosen logical operation. An SOA (11) element receives such input signals to be piloted thereby in saturation and its output is connected to at least one optical filter (14, 15, 16) that filters components of signals output from the SOA and which represent a desired logical result of the signals input at the gate so that at the output (13) of the filter there is an optical signal as the result of the desired logical operation. A probe signal (17) can also be provided. An appropriate combination of power of the input, power and probe signal wavelength and central wavelength of the filter allows obtaining a plurality of logic functions such as NOR, NOT, inverted XOR, AND, OR.

Abstract: An electrical return to zero (RZ) encoder converts non-return to zero (NRZ) data, into of RZ data patterns with a flexibility for duty cycle adjustment so that any RZ data pattern may be provided for a specific application's need. A duty cycle of>50% or<50% may be achieved by selecting between a clock signal or its complement and adjusting its delay.

Abstract: An all-optical logic gates comprises a nonlinear element such as an optical resonator configured to receive optical input signals, at least one of which is amplitude-modulated to include data. The nonlinear element is configured in relation to the carrier frequency of the optical input signals to perform a logic operation based on the resonant frequency of the nonlinear element in relation to the carrier frequency. Based on the optical input signals, the nonlinear element generates an optical output signal having a binary logic level. A combining medium can be used to combine the optical input signals for discrimination by the nonlinear element to generate the optical output signal. Various embodiments include all-optical AND, NOT, NAND, NOR, OR, XOR, and XNOR gates and memory latch.

Abstract: Various embodiments of the present invention are directed to methods for determining a phase shift acquired by an entangled N-qubit system represented by a NOON state. In one embodiment, a probe electromagnetic field is coupled with each qubit system. The phase shift acquired by the qubit systems is transferred to the probe electromagnetic field by transforming each qubit-system state into a linear superposition of qubit basis states. An intensity measurement is performed on the probe electromagnetic field in order to obtain a corresponding measurement result. A counter associated with a measurement-result interval is incremented, based on the measurement result falling within the measurement-result interval. A frequency distribution is produced by normalizing the counter associated with each measurement-result interval for a number of trials.

Abstract: An all-optical logic gates comprises a nonlinear element such as an optical resonator configured to receive optical input signals, at least one of which is amplitude-modulated to include data. The nonlinear element is configured in relation to the carrier frequency of the optical input signals to perform a logic operation based on the resonant frequency of the nonlinear element in relation to the carrier frequency. Based on the optical input signals, the nonlinear element generates an optical output signal having a binary logic level. A combining medium can be used to combine the optical input signals for discrimination by the nonlinear element to generate the optical output signal. Various embodiments include all-optical AND, NOT, NAND, NOR, OR, XOR, and XNOR gates and memory latch.

Abstract: A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

Abstract: An optical transmission device includes an optical phase modulator and a signal generation function. The optical phase modulator is controlled, so that when the state of an intensity-modulated optical signal shifts from a first luminescent state, through a non-luminescent state, to a second luminescent state, the phase of the optical signal in the first luminescent state and the phase of the optical signal in the second luminescent state are inverted with respect to each other, or so that when the state of the intensity-modulated optical signal shifts from the first luminescent state, through two or more non-luminescent states, to a third luminescent state, the phase of the optical signal in the first luminescent state and the phase of the optical signal in the third luminescent state are inverted with respect to each other.

Abstract: Quantum testing can compare unknown photon states in a manner suitable for a validation check of a quantum digital signature, testing of the operation of a quantum gate, or detecting of entanglement. The effect of the QSC system can be used to entangle input photon states. QSC system can include a control swap gate having a control channel that is measured, a beam splitter and a controlled phases gate with a control channel that is measured, or a beam splitter with a parity detector on an output channel. The operation of the QSC system can also be used to generate an entangled photon state.

Abstract: An optical switch and optical storage loop are used as the basis of a single-photon source and a quantum memory for photonic qubits. To operate as a single-photon source, the techniques include a source of a pair of photons, such as a parametric down-conversion crystal, which is known to emit photons in pairs. The detection of one member of the pair activates the switch, which re-routes the other member into the storage loop. The stored photon is then known to be circulating in the loop, and can be switched out of the loop at a later time chosen by the user, providing a single photon for potential use in a variety of quantum information processing applications. To operate as a quantum memory for photonic qubits, a single-photon in an arbitrary initial polarization state is coherently stored in the loop, and coherently switched out of the loop when needed.

Abstract: A variety of structures, methods, systems, and configurations can support plasmons for logic.

Abstract: The invention is directed to apparatus, methods, systems and computer programs which permit a simplification or reduction of the description of a complex digital circuit. This is accomplished by using a completely new system of propositional logic (13B), representing the logic of a logical circuit to be designed as points and vectors in a vector space, simplifying the logic so represented to a simpler form using vector transformations, and designing the circuit using the simpler form. The invention is also directed to apparatus, methods, systems and devices which will implement the vector logic system in optical forms, including free-space optical methods, flat-optical methods, colorimetric methods, and methods using a polarization-based AND-gate.

Abstract: Disclosed herein is an apparatus and method for implementing an all-optical OR logic gate. The apparatus includes an optical pulse generator, a Mode-Locked Fiber Laser (MLFL), a first optical splitter, a first optical delay line means, an optical control means, a first optical coupler, a second optical splitter, a second optical delay line means, a third optical splitter, an Erbium Doped Fiber Amplifier (EDFA), a Semiconductor Optical Amplifier (SOA), a second optical coupler, and an optical analyzer. The first optical splitter divides light output from the MLFL. The first and second optical delay line means acquire time delay. The optical control means controls intensity and polarization of the light. The first optical coupler generates the first input signal pattern as a probe signal. The second optical splitter divides light output from the first optical coupler. The third optical splitter divides the second input signal pattern.

Abstract: Disclosed herein is an apparatus and method for controlling the optical output of a mobile display using a single-panel type diffractive light modulator. The apparatus includes a surrounding light amount information storage unit and an optical output adjusting means. The surrounding light amount information storage unit stores information about the amount of surrounding light. The optical output adjusting means adjusts the output values of red, green and blue light sources based on the information about the amount of surrounding light.

Abstract: An apparatus for generating a quantum state of a two-qubit system including two qubits, each qubit being represented by a particle which invariably travels through one of two paths, includes a quantum gate composed of an interferometer for implementing an-interaction-free measurement. The apparatus receives two particles having no correlation and generates a Bell state with asymptotic probability 1. A Bell measurement of a state of a two-qubit system is performed by observing a quantum gate composed of the interferometer after the quantum gate has processed the state and selecting the state from the Bell bases. An approximate fidelity of a quantum gate composed of the interferometer is calculated, if an absorption probability with which a first particle absorbs a second particle in the interferometer is less than 1, under the condition that the number of times the second particle hits beam splitters in the interferometer is sufficiently large.

Abstract: A switching element capable of being used in an optical processing device includes an optical signal separator operable to separate a multiple wavelength optical signal into one or more optical signal wavelengths. The switching element further includes a plurality of semiconductor optical amplifiers located on a single semiconductor substrate. The plurality of semiconductor optical amplifiers operable to perform an optical switching operation on at least one of the optical signal wavelengths. The switching element also includes a controller operable to generate a control signal that affects the optical switching operation performed by one or more of the plurality of semiconductor optical amplifiers.

Abstract: Nonlinear electromagnetic elements can efficiently implement quantum information processing tasks such as controlled phase shifts, non-demolition state detection, quantum subspace projections, non-demolition Bell state analysis, heralded state preparation, quantum non-demolition encoding, and fundamental quantum gate operations. Direct use of electromagnetic non-linearity can amplify small phase shifts and use feed forward systems in a near deterministic manner with high operating efficiency. Measurements using homodyne detectors can cause near deterministic projection of input states on a Hilbert subspace identified by the measurement results. Feed forward operation can then alter the projected state if desired to achieve a desired output state with near 100% efficiency.

Abstract: Method and an optical computation device for obtaining an indication about the existence of a feasible solution for a bounded instance of a problem that belongs to the non-deterministic polynomial class of problems, using parallel optical computations employing a multitude of light rays simultaneously propagating along paths in an optical arrangement. An optical arrangement that can implement a universal non deterministic Turing Machine that can solve bounded instances of problems of the class is determined. An initial incoming ray is directed to a point in the optical arrangement, that represents the initial configuration of the universal non deterministic Turing Machine, such that the initial configuration corresponds to the bounded instance. Each incoming ray is split within the optical arrangement into two or more outgoing rays at pre-determined locations in the optical arrangement.

Abstract: An optical latch based on a lasing semiconductor optical amplifier is disclosed. The optical latch is configured to achieve one or more stable states in response to the input of predetermined signals at a “SET” input and a “RESET” input of the optical latch. The optical latch includes first and second LSOAs, each of which is configured to receive a pump input and generate an amplifier output. Each LSOA is also associated with a respective combiner and splitter. The combiner associated with each LSOA combines an input signal from the “SET” or “RESET” input, as applicable, with a signal received from the splitter of the other LSOA and the resulting combined signal is then input to the LSOA. Each splitter receives a ballast laser output from the associated LSOA, which is then split into two signals, namely, an input to the combiner of the other LSOA and an output signal.

Abstract: Quantum computer includes optical systems arranged in series each of the plurality of optical systems includes first half-wave plate, first polarizing beam splitter, first switching mirror, first photodetector, first polarization rotator, optical cavity which contains atom, second switching mirror, second photodetector, second polarization rotator, and high reflection mirror, first polarization beam splitter outputting third light beam received from first switching mirror or second switching mirror to adjacent one of optical systems, third switching mirrors each provided between adjacent two optical systems, each of third switching mirrors reflecting or transmitting light beam output from one of two optical systems, light sources each providing light beam to corresponding optical system, and measurement system which measures polarization of incoming light beam.

Abstract: The present invention relates to an apparatus and a method for realizing all-optical NOR logic device using the gain saturation characteristics of a semiconductor optical amplifier(SOA). More particularly, the invention relates to a 10 Gbit/s all-optical NOR logic device among all-optical logic devices, in which a signal transmitted from a given point of an optical circuit such as an optical computing circuit is used as a pump signal and a probe signal.

Abstract: This disclosure is concerned with digital optical circuits, including an optical astable multivibrator. In one example, an optical astable multivibrator is provided that includes a lasing semiconductor optical amplifier (LSOA), such as a VLSOA for example. The LSOA is optically coupled to a time delay component and includes a pump input, amplifier input, amplifier output, and a ballast laser output. The time delay component includes an input that is optically coupled with the ballast laser output of the LSOA. The time delay component further includes an output that is optically coupled with the amplifier input of the LSOA. The output of the LSOA is a clock signal having a periodic square waveform whose frequency is determined by the time delay component.

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: There is provided an apparatus for processing a segment of x optical bit slots from a packet comprising y optical bit slots, each bit slot defining a respective one of first and second complementary logical states, within a time span shorter than or equal to the time for receipt of the packet. The apparatus including a segment replicator which generates serial copies of the segment of the packet, each copy residing within a respective word containing z bit slots, where z is equal to or greater than x; and a bit differential processor for processing successive bits of the successive copies of the segment in n successive processing steps, the product of n and z being less than or equal to y. The result of each processing step is output in sequence by the bit differential processor, the result of processing the segment being given by x successive bit slots of the output.

Abstract: An optical switch and optical storage loop are used as the basis of a single-photon source and a quantum memory for photonic qubits. To operate as a single-photon source, the techniques include a source of a pair of photons, such as a parametric down-conversion crystal, which is known to emit photons in pairs. The detection of one member of the pair activates the switch, which re-routes the other member into the storage loop. The stored photon is then known to be circulating in the loop, and can be switched out of the loop at a later time chosen by the user, providing a single photon for potential use in a variety of quantum information processing applications. To operate as a quantum memory for photonic qubits, a single-photon in an arbitrary initial polarization state is coherently stored in the loop, and coherently switched out of the loop when needed.

Abstract: Techniques are provided that use the quantum Zeno effect to implement practical devices that use single photons as the qubits for quantum information processing. In the quantum Zeno effect, a randomly-occurring event is suppressed by frequent measurements to determine whether the event has occurred. The same results can be obtained by using atoms or molecules or ions to react to the occurrence of the event. Techniques include directing one or more input qubits onto a device and applying a quantum Zeno effect in the device. The quantum Zeno effect is applied by consuming one or more photons in the device under conditions in which photons, that would otherwise be output by the device, do not represent a result of a particular quantum information processing operation. Devices implemented using the quantum Zeno effect can operate with low error rates without the need for high efficiency detectors and large number of ancilla.

Abstract: An optical AND logic gate includes a summing gate having first and second inputs for receiving first and second optical signals, and a threshold device. The gate produces an output corresponding to the AND product of the first and second optical signals. In another version the AND gate includes first and second inputs for receiving first and second optical signals, and an optical loop for producing an output corresponding to the AND product of the first and second optical signals. In an alternative versions a NAND gate is provided by applying an optical logic NOT on an AND gate.

Abstract: The method according to the present invention includes the steps of inputting an optical signal having a first wavelength and probe light having a second wavelength different from the first wavelength into a nonlinear optical medium, broadening the spectrum of the probe light through cross phase modulation between the optical signal and the probe light inside the nonlinear optical medium, and extracting a signal component including a modulated component of the optical signal and having a band narrower than the band of the spectrum broadened. According to the present invention it can be possible to provide a method and device which can easily convert the wavelength of signal light into an arbitrary wavelength in performing optical 3R functions.

Abstract: An all-optical, asynchronous binary storage cell implemented by optically induced total internal reflection cross-junction waveguide switches. The term “all-optical” refers to directing of optical data signals as a result of optical control signal inputs without the need for conversion between optical and electrical domains. The binary cell is a building block for a programmable all-optical random access memory (AORAM) device. The AORAM device enables circuits and networks that require optical buffers.

Abstract: A switching element capable of being used in an optical processing device includes an optical signal separator operable to separate a multiple wavelength optical signal into one or more optical signal wavelengths. The switching element further includes a plurality of semiconductor optical amplifiers located on a single semiconductor substrate. The plurality of semiconductor optical amplifiers operable to perform an optical switching operation on at least one of the optical signal wavelengths. The switching element also includes a controller operable to generate a control signal that affects the optical switching operation performed by one or more of the plurality of semiconductor optical amplifiers.

Abstract: The present invention relates to a method of embodying all-optical XOR logic gate by using semiconductor optical amplifier, and more particularly, to a technique to embody all-optical XOR logic gate utilizing the cross-gain modulation (XGM) characteristic of semiconductor optical amplifiers controllable with input currents, illumination signal, and pumping signal. The method of all-optical XOR logic element in accordance with the present invention is characterized to obtain operational characteristic of the all-optical XOR logic element by inputting pump-signal and illumination signal concurrently into two semiconductor optical amplifiers and then summing the two output signals having XGM characteristic arising from gain saturation and wavelength conversion of the semiconductor optical amplifiers.

Abstract: An optical memory having an input port for receiving an input optical signal to be stored in the optical memory is disclosed. A portion of the optical signal is coupled to a storage loop for storing optical signals by a coupler that transfers a portion of the input optical signal to the storage loop. An optical signal stored in the storage loop is output by coupling a portion of that optical signal to a first external optical waveguide. The storage loop includes a semiconductor optical amplifier for amplifying the signals stored in the storage loop to compensate for losses incurred by those signals in traversing the storage loop. A plurality of such optical memories can be combined to form a larger memory that includes a reconditioning circuit that resets the amplitude of the optical signals to a value that depends on the amplitude of the optical signals.

Abstract: An optical cross-connect system is disclosed that use reduces the number of AWGs (Arrayed-Waveguide Grating) as compared to prior art systems so that the hardware complexity is reduced while simultaneously reducing its production costs. The optical cross-connect system includes N×N AWGs for performing multiplexing/demultiplexing functions, an optical circulator for transmitting bidirectional signals via the AWGs, an optical coupler for interconnecting N individual ports of the AWGs, and an optical switching block connected to the optical coupler. One of the optical signals branched from the optical coupler is input to the optical switching block having a corresponding wavelength and distributed to a desired output terminal, and the other one of the optical signals is input to an optical switching block being out of an operable wavelength range and filtered by the optical switching block.

Abstract: A MEMS type optical switch includes a substrate, the substrate including at least one groove formed therein; first and second optical fibers disposed in the at least one groove, the at least one groove including a widened portion for movement of at least one of the first and second optical fibers; a thermal actuator disposed adjacent one of the first and second optical fibers, the thermal actuator comprising at least one v-beam, a pair of anchors connected to ends of the v-beam, and a yoke disposed in a central portion of the v-beam.

Abstract: Optical logic circuits are based on lazing semiconductor optical amplifiers, such as vertical lazing semiconductor optical amplifiers. For example, one or more VLSOAs with selected depletion thresholds are combined to form various optical logic devices.

Abstract: An optical switching system that switches the output port of an optical signal as indicated by address information (a label) that is contained in optical data packets constituting the optical signal. The optical switching system reads the address information by detecting the electric power level of a label signal that has been subjected to an optical angular modulation, passed through an optical filter and been subjected to an optical detection.

Abstract: An optical control electromagnetic wave circuit comprises a unit composed of a semiconductor layer, a transparent substrate, and a transparent grounded conductive layer and a displaying unit. The semiconductor layer is formed on the transparent substrate, and the photoconductive layer is formed on the opposite surface of the transparent substrate. The displaying unit faces the transparent grounded layer. The shape of the radio wave circuit which is displayed on the displaying unit is mapped on the semiconductor layer to form the radio wave circuit. It can be realized to dynamically change the radio wave circuit by changing the shape of the radio wave circuit displayed on the displaying unit. The radio wave circuit can be provided freely and flexibly.

Abstract: Quantum switches, referred to as trisistors, operate on the basis of interactions between two elementary particles (EP), such as photons, electrons, phonons, etc. A first EP is used as a control input to the trisistor and interacts with a second EP, thereby inducing a detectable state change in the second EP that determines the trisistor's output value. The physical property which determines the particular EP state could be, for example, polarization, spin direction or energy level. The trisistors are connected primarily in series rather than in parallel as in previous quantum computing devices. The trisistors can be combined to form various types of logic gates, circuits, and other computer components. To implement the changes of state of the trisistors, one preferred embodiment employs nonlinear optics using a thin section of crystal.

Abstract: The present invention is related to an all-optical OR device embodied by using the gain saturation and wavelength conversion characteristics of semiconductor optical amplifier (SOA), and more particularly, to a technique to embody an all-optical OR gate that performs all-optical logic operation by utilizing optical signals transmitted at arbitrary points of optical circuits such as optical computing circuits as the pump signal and the probe signal.

Abstract: An optical pulse pattern generator can generate optical pulse signals with various periods and patterns. It supplies an optical pulse from an optical pulse source to a variable optical delay line circuit including cascade-connected characteristic-variable asymmetrical Mach-Zehnder interferometers via an optical combiner and splitter. The optical pulse is fed back to the optical combiner and splitter from the final stages of the cascade-connected characteristic-variable a symmetrical Mach-Zehnder interferometers via an optical exclusive OR circuit and optical amplifier. Making directional couplers with variable coupling ratio, and directional couplers with variable coupling ratio in operation can cause the final stage of the cascade-connected characteristic-variable asymmetrical Mach-Zehnder interferometer to produce a random pulse train.

Abstract: The present invention relates to an implementation method of all-optical half adder by using semiconductor optical amplifier(SOA)-based devices and the apparatus thereof. In more detail, it relates to an implementation method of all-optical half adder comprising an all-optical XOR gate and an all-optical AND gate, implemented by using SOA-based devices, and an apparatus thereof.

Abstract: A bi-stable micro-actuator is formed from a first and a second silicon-on-insulator wafer fused together at an electrical contact layer. A cover with a V-groove defines an optical axis. A collimated optical signal source in the V-groove couples an optical signal to an optical port in the V-groove. A mirror surface on a transfer member blocks or reflects the optical signal. The transfer member has a point of support at the first and second end. The mirror blocks or reflects the optical axis. An expandable structure applies a compressive force between the first and second point of support of the transfer member along a compressive axis to hold the transfer member in a bowed first state or a bowed second state. A control signal applied to a heating element in the expandable structure reduces the compressive force, switching the transfer member to a second state.

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: A first multimode interferometer has a first input port to which an optical signal is applied, a first output port, and a second output port. A first optical waveguide is connected to the first output port of the first multimode interferometer. The first optical waveguide has a refractive index changed in response to a trigger signal externally applied. A second optical waveguide is connected to the second output port. A triggering unit supplies, to the first optical waveguide, the trigger signal for changing the refractive index of the first optical waveguide. An optical switch is provided which can increase the processing speed, can reduce the device size, and is free from dependency on the polarization state of an optical signal.

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.