Abstract: A high-quality image is taken by a solid-state imaging element that detects an address event. The solid-state imaging element is provided with a pixel array unit and an analog-to-digital conversion unit. In the pixel array unit in the solid-state imaging element, a normal pixel that generates an analog signal by photoelectric conversion of incident light and outputs the analog signal and a detection pixel that detects that an amount of change in incident light becomes larger than a predetermined threshold and outputs a detection result are arranged. Furthermore, the analog-to-digital conversion unit converts the analog signal into a digital signal.

Abstract: An apparatus for generating a time-delayed product of two independent signals includes a fixed-wavelength laser. A first optical modulator is optically coupled to the fixed-wavelength laser and configured to modulate a fixed wavelength optical carrier with a first input signal of a set of input signals. The apparatus also includes a tunable laser. A second optical modulator is optically coupled to the tunable laser and configured to modulate a tunable optical carrier with a second input signal of the set of input signals. The apparatus also includes a dispersive element coupled to the second optical modulator, a first optical detector coupled to the dispersive element, a third optical modulator optically coupled to the first optical detector and the first optical modulator, an optical 90-degree hybrid element optically coupled to the third optical modulator, and a plurality of optical detectors optically coupled to the optical 90-degree hybrid element.

Abstract: A Digital-to-Analog Converter, DAC, is provided. The DAC comprises one or more first DAC cells configured to generate a first analog signal based on first digital data. The one or more first DAC cells are coupled to a first output node for coupling to a first load. The DAC comprises one or more second DAC cells configured to generate a second analog signal based on second digital data. The one or more second DAC cells are coupled to a second output node for coupling to a second load. The one or more first DAC cells and the one or more second DAC cells are couplable to a power supply for drawing a supply current. The DAC further comprises a data generation circuit configured to generate the second digital data based on the first digital data.

Abstract: An optical IQ modulator includes: Y branching elements, which are cascade-connected, each of which has one input and two outputs; QPSK modulators configured to perform QPSK modulation on continuous light branched by the Y branching elements to generate signal light; and Y combining elements, which are cascade-connected, each of which has two inputs and one output.

Abstract: The present disclosure relates to an electronic load apparatus. An embodiment of the present disclosure includes an electronic load apparatus including: a measurement resistor, a reference circuit, a transistor, and a feedback circuit. The measurement resistor includes a first contact, a second contact, a third contact, and a fourth contact. The first contact and the second contact are located at a first end of the measurement resistor. The third contact and the fourth contact are located at a second end of the measurement resistor. A reference power (or a reference voltage) electrically connects to the reference circuit. The reference circuit and the first contact of the measurement resistor are electrically connected. The transistor includes a drain, a gate, and a source. The reference circuit and the gate of the transistor are electrically connected. One of the source and the drain of the transistor electrically connects to the second contact of the measurement resistor.

Abstract: This application provides example signal processing apparatus and example signal processing method. One example signal processing apparatus includes a sampling unit, a beam combiner, and an optical resonator. The sampling unit is connected to the beam combiner, and the beam combiner is connected to the optical resonator. The sampling unit is configured to sample an analog signal by using an optical pulse signal to output a sampled optical pulse signal. The beam combiner is configured to combine the sampled optical pulse signal and a multi-wavelength optical signal into a first optical signal. The optical resonator is configured to perform resonance based on the first optical signal to output a second optical signal in the first optical signal, where a wavelength of the second optical signal is equal to a resonant wavelength of the optical resonator.

Abstract: An apparatus for generating a time-delayed product of two independent signals includes a fixed-wavelength laser. A first optical modulator is optically coupled to the fixed-wavelength laser and configured to modulate a fixed wavelength optical carrier with a first input signal of a set of input signals. The apparatus also includes a tunable laser. A second optical modulator is optically coupled to the tunable laser and configured to modulate a tunable optical carrier with a second input signal of the set of input signals. The apparatus also includes a dispersive element coupled to the second optical modulator, a first optical detector coupled to the dispersive element, a third optical modulator optically coupled to the first optical detector and the first optical modulator, an optical 90-degree hybrid element optically coupled to the third optical modulator, and a plurality of optical detectors optically coupled to the optical 90-degree hybrid element.

Abstract: An apparatus for generating a set of spectral correlation coefficients of an input signal includes: a master laser configured to generate an optical frequency comb signal; a first optical modulator configured to modulate the optical frequency comb signal with an input signal to generate a plurality of spectral copies of the input signal; a dispersive element configured to delay the plurality of spectral copies of the input signal by a wavelength-dependent time delay; a second optical modulator configured to modulate the delayed plurality of spectral copies with a conjugate of the input signal; and an optical comb filter configured to integrate the conjugate modulated plurality of spectral copies of the input signal to generate a set of cyclic autocorrelation coefficients.

Abstract: A signal processing device included in an optical reception device configured to receive a burst optical signal transmitted by one of a plurality of optical transmission devices, includes a symbol timing detecting unit configured to detect a symbol timing based on sample signals obtained by oversampling the burst optical signal converted into an electric signal with a sampling rate higher than a symbol rate, an adaptive equalization filter unit configured to perform an equalization process on the sample signals, and a timing matching unit configured to match timing such that, when the adaptive equalization filter unit takes in the sample signals, one of the taken-in sample signals corresponding to the symbol timing is given to a tap of which a tap coefficient has a maximum value among taps included in the adaptive equalization filter unit.

Abstract: A non-uniform sampling pADC is disclosed. The pADC may include an optical pulse source configured to generate uniform optic pulses. The pADC may include a non-uniform sampling system. The non-uniform sampling system may include an inter-pulse timing modulation sub-system configured to convert the uniform optic pulses into non-uniform optic pulses. The non-uniform sampling system may include a timing control sub-system configured to control the timing of the optical pulse source. The pADC may include an optical modulator configured to modulate the non-uniform optical pulses. The pADC may include a photodetector configured to convert the modulated non-uniform optic pulses into electronic pulses. The pADC may include a pulse capture assembly configured to capture a pulse amplitude of the electronic pulses and generate sampled radio frequency output pulses. The pADC may include a quantizer configured to quantize the sampled radio frequency output pulses and generate digital radio frequency output signals.

Abstract: Methods and apparatuses for downconverting are provided. A dual-drive mach zehnder modulator (DDMZM) receives: a continuous wavelength optical signal, an input signal (microwave signal), and local oscillator tones. The DDMZM includes: first and second arms formed from optical waveguides which receive the optical signal, a first modulator that receives the input signal, and a second modulator that receives the oscillator tones. The input signal is modulated onto the optical signal propagating through the first arm to form a first modulated optical signal. The oscillator tones and third-order intermodulation products of those tones are modulated onto the optical signal propagating through the second arm to form a second modulated optical signal. The modulated optical signals are combined to form an output optical signal. The oscillator tones are spaced two folded bandwidths apart and centered within a spectrum of interest of the input signal.

Abstract: Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates fall amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods.

Abstract: A computing system comprising a portable computer and a reader are disclosed. The portable computer is pocket-sized and comprises flash memory, and optionally a processor and a GPS chip. The reader includes a monitor, a keyboard with docking port and an optional processor and at least one input/output USB connector. A user cannot interact with the portable computer without the reader. The reader is a non-functioning “shell” without the portable computer, however, when they are connected the system becomes a fully functional personal computer. To log on, a user provides security information, for example, a password or biometrics, such as fingerprints. The credit card size and capabilities of the portable computer allows a user to easily carry virtually their entire computer in a pocket for use anywhere there is a reader. In addition, the portable computer provides security against unauthorized use, even if lost or stolen.

Abstract: A graphics adjustment system detects the video resolution of digital video to be output by a receiving device and saves the graphics settings input by the user when the user adjusts the graphics settings on the receiving device such that the digital video being presented in the presentation device is not cut off due to overscanning. The system saves the graphics adjustment settings as the setting to use going forward for digital video of that same resolution for that particular presentation device. In this manner, the digital video output from the receiving device will not be cut off when presented on the presentation device, even when the receiving device is switching between receiving digital video programming of different resolutions from various program distributors and/or the content providers.

Abstract: An apparatus for generating a set of spectral correlation coefficients of an input signal includes: a master laser configured to generate an optical frequency comb signal; a first optical modulator configured to modulate the optical frequency comb signal with an input signal to generate a plurality of spectral copies of the input signal; a dispersive element configured to delay the plurality of spectral copies of the input signal by a wavelength-dependent time delay; a second optical modulator configured to modulate the delayed plurality of spectral copies with a conjugate of the input signal; and an optical comb filter configured to integrate the conjugate modulated plurality of spectral copies of the input signal to generate a set of cyclic autocorrelation coefficients.

Abstract: A signal converter, including: a power circuit, a microprocessor, a plurality of input signal interface circuits, a first multiplexer switch, and an output signal interface circuit. The power circuit supplies power for each circuit of the signal converter. The plurality of input signal interface circuits is disposed side by side, and in operation, one of the plurality of input signal interface circuits is connected to the first multiplexer switch to work. The plurality of input signal interface circuits includes input terminals and output terminals. The input terminals receive corresponding input signals, and the output terminals are connected to the microprocessor. The microprocessor includes an output terminal which is connected to the output signal interface circuit. The microprocessor controls the first multiplexer switch to connect to one of the plurality of input signal interface circuits.

Abstract: A laser master-oscillator power-amplifier (MOPA) is operated to provide successive bursts of ultrashort pulses. The pulse-bursts are selected by an optical modulator from a pulse train delivered by the master oscillator prior to amplification in the power amplifier. The optical modulator has a selectively variable transmission specified by an analog voltage signal having a stepped waveform. The voltage signal is delivered by a sequentially-switched parallel switch-array connected in parallel with a parallel DAC having multiple parallel DC voltage outputs corresponding to steps of the stepped waveform.

Abstract: A system for analog-to-digital conversion, preferably including one or more optical inputs, optical sources, phase remodulators, and/or photonic circuits, and optionally including detector banks and/or digital electronics. A method for analog-to-digital conversion, preferably including receiving an optical input signal, generating a phase-modulated optical signal, and/or generating a plurality of optical outputs, and optionally including generating a plurality of electrical outputs and/or encoding a digital representation of the outputs.

Abstract: Apparatus and/or method for performing single-shot network analysis of electrical, electronic and electro-optical elements (e.g., components, circuits, modules, sub-systems and/or systems) on a device, or devices, under test (DUT). A pulsed optical source is directed through a first dispersion element to an modulator, while a delayed version of the pulsed optical source is directed to the DUT (pulsed optical source converted to electrical signal if DUT has electrical input), whose electrical output is fed to the modulator whose modulated optical pulse output is stretched through a second optical dispersion element, then converted to an electrical signal and processed to provide analysis and/or display of DUT response.

Abstract: A system and method to convert a wideband optical signal to a multi-bit digital electrical signal using a superconducting integrated circuit. In a preferred embodiment, the optical signal modulates the phase (i.e., adjusts the timing) of a sequence of single-flux-quantum voltage pulses. The optoelectronic modulator may comprise an optically tunable Josephson junction, superconducting inductor, or bolometric detector, with switching speeds approaching 100 ps or less. The optical signal may comprise a plurality of optical signals such as a wavelength-division multiplexed signal. The optical-to-digital converter may be applied to high-speed digital communication switches, broadband digital input/output for superconducting or quantum computing, and control/readout of detector arrays.

Abstract: A high-speed and high-precision photonic analog-to-digital conversion device capable of realizing intelligent signal processing. Learning ability of deep learning technology is utilized to learn the nonlinear response and channel mismatch effect of the system and configure optimal parameters of the deep network. Deterioration of photonic analog-to-digital conversion system performance caused by nonlinear distortion and channel mismatch distortion is eliminated in real time, and performance indicators thereof are improved. By using the induction and deduction ability of deep learning technology, intelligent signal processing of the input signal is realized, and users are provided with digital signals that meet the requirements.

Abstract: Systems and methods are provided for presenting visual media on a structure having a plurality of unordered light sources, e.g., fiber optic light sources, light emitting diodes (LEDs), etc. Visual media can be created based on a computer model of the structure. Images of the structure can be analyzed to determine the location of each of the light sources. A lookup table can be generated based on the image analysis, and used to correlate pixels of the visual media to one or more of the actual light sources. A visual media artist or designer need not have prior knowledge of the order/layout of the light sources on the structure in order to create visual media to be presented thereon.

Abstract: A computing system comprising a portable computer and a reader are disclosed. The portable computer is pocket-sized and comprises flash memory, and optionally a processor and a GPS chip. The reader includes a monitor, a keyboard with docking port and an optional processor and at least one input/output USB connector. A user cannot interact with the portable computer without the reader. The reader is a non-functioning “shell” without the portable computer, however, when they are connected the system becomes a fully functional personal computer. To log on, a user provides security information, for example, a password or biometrics, such as fingerprints. The credit card size and capabilities of the portable computer allows a user to easily carry virtually their entire computer in a pocket for use anywhere there is a reader. In addition, the portable computer provides security against unauthorized use, even if lost or stolen.

Abstract: An image sensor includes a pixel array and a peripheral circuit. The peripheral circuit is electrically connected to the pixel array and includes a logic block and at least one redundancy block to replace the logic block when the logic block is a defective block.

Abstract: A photonic feedforward analog-to-digital converter (ADC) is provided. According to one aspect of the invention, the signal to be digitized is applied to only one electro-optic modulator. High speed is achieved by taking advantage of the fundamental property of a Pockels Cell to control wave polarization using the electro-optic effect. In a further aspect, once a bit is determined, its state is fed forward to the next least significant bit to aid in determination of the next lower bit. This nonlinear feedforward aspect of the ADC provides simplicity of its architecture.

Abstract: Techniques relate to reading a qubit coupled to a microwave resonator. A microwave signal at a microwave resonator frequency is input to the microwave resonator that couples to the qubit. A microwave readout signal from the microwave resonator is output to a microwave to optical converter. The microwave readout signal includes a qubit state of the qubit. The microwave to optical converter is configured to convert the microwave readout signal to an optical signal. In response to the optical signal being output by the microwave to optical converter, it is determined that the qubit is in a predefined qubit state. In response to no optical signal being output by the microwave to optical converter, it is determined that the qubit is not in the predefined qubit state.

Abstract: The present invention embraces a method to obtain barcoded information off a computer screen under high ambient lighting conditions, including a direct sunlight environment. The method includes a user prompting a computer to present an active window on all or a portion of its screen. The computer generates a communication sequence, comprising information commonly included on a barcode, and displays the communication sequence on the computer screen. After activating the scanner into an alternative or screen mode, the user places the scanner on the active window of the computer screen and the scanner asynchronously receives the communication sequence. The scanner decodes the received communication sequence and obtains encoded information of the computer. The encoded information may include a unique identifier of the computer, such as a MAC address. With the MAC address, the scanner may wirelessly communicate with the computer to exchange other information.

Abstract: A symmetric data encryption system configured to receive a data stream to be encoded; to relate segments of the data stream with a predetermined distortion-inducing amplitude of light to encrypt the data stream; to transmit the data stream; to decrypt the data stream by compensating for the value induced by the distortion-inducing amplitude of light; wherein the distortion-inducing amplitude of light relates to different wavelengths of light emitted by one or more of a plurality of light sources in a non-uniform manner so the effect of the distortion-inducing amplitude of light is difficult to predict, thereby providing obfuscation and encryption of the data stream.

Abstract: An integrated and networked system of remote operations is provided that extends remote expert NDT methodology to a variety of manufacturing and in-service processes. The functional elements of the system comprise remote NDT applications, advanced remote NDT, remote administration, remote NDT commercial operations, and remote data analytics, which are all tied together by a remote communications hub. The communications hub has communication links with computer systems of those functional elements.

Abstract: A high-speed analog-to-digital converter can produce a digital signal representative of an analog input electrical signal. An optical amplitude modulator can modulate an input optical pulse train using the analog input electrical signal. An optical splitter can split the modulated optical pulse train into a plurality of modulated optical pulse trains. Optical path delays can stagger in time the modulated optical pulse trains to form a plurality of time-staggered modulated optical pulse trains. Demodulators can detect and filter the time-staggered modulated optical pulse trains to form a respective plurality of time-averaged voltages. Analog-to-digital converters can output a respective plurality of digital time series representative of the respective time-averaged voltages. An interleaver can aggregate the plurality of digital time series to form the digital signal, which has a sample rate greater than a repetition rate of the input optical pulse train.

Abstract: Under one aspect, a method for performing a linear algebra operation includes imposing matrix elements onto a chirped optical carrier; inputting into a multi-mode optic the matrix elements imposed on the chirped optical carrier; outputting by the multi-mode optic a speckle pattern based on the matrix elements imposed on the optical carrier; and performing a linear algebra operation on the matrix elements based on the speckle pattern. The matrix elements can be from matrix A and a vector b, and the multi-mode optic can optically transform each of matrix A and vector b by a speckle transformation S, so as to output a speckle pattern including elements of a matrix SA of dimension p,n and matrix elements of a vector Sb of dimension p. The linear algebra operation can include generating {tilde over (x)}=(SA)†Sb, wherein † indicates a pseudo-inverse operation.

Abstract: A method of performing optical serial-to-parallel conversion of an optical signal includes performing phase modulation of the optical pulse stream and outputting a phase-modulated optical signal as a result thereof. The method also includes performing optical switching of the phase-modulated optical signal by optical switches connected to each other in a series relationship on a signal path. The method further includes performing optical switching of a reference optical clock signal by optical switches connected to each other in a series relationship on a reference path.

Abstract: A symmetric data encryption system configured to receive a data stream to be encoded; to relate segments of the data stream with a predetermined distortion-inducing amplitude of light to encrypt the datastream; to transmit the datastream; to decrypt the data stream by compensating for the value induced by the distortion-inducing amplitude of light; wherein the distortion-inducing amplitude of light relates to different wavelengths of light emitted by one or more of a plurality of light sources in a non-uniform manner such that the effect of the distortion-inducing amplitude of light is difficult to predict, thereby providing obfuscation and encryption of the datastream.

Abstract: An analog-to-digital converter can produce a digital signal representative of an analog input electrical signal. A continuous-wave laser can lock to a multifrequency optical signal and produce a continuous-wave optical signal. An optical amplitude modulator can modulate the continuous-wave optical signal using the analog input electrical signal to produce a first modulated optical signal. An optical splitter can split the first modulated optical signal into a plurality of modulated optical signals. A plurality of detectors can convert the modulated optical signals into respective modulated electrical signals. A plurality of comparators and a decoder arranged in a flash converter topology can receive the modulated electrical signals and output the digital signal using a timing reference derived from the multifrequency optical signal. Using a relatively high-precision multifrequency optical signal, such as produced by a photonic oscillator, can produce a relatively high-precision device.

Abstract: A voltage-mode integrate-and-dump photonic ADC front-end circuit includes a current integrator for immediately integrating current pulses onto a capacitor voltage, the current pulses converted by photodetectors from optical data pulses corresponding to a received analog input signal. The circuit may include dampeners for reducing voltage ringing and resulting intersymbol interference (ISI) to preserve SNR at high data rates. The integrating capacitor may be discharged by a reset switch based on clock signals generated by a master clock; the reset switch may include a pulse width controller enabling the integrating capacitor to track and hold the integrated voltage, rather than downstream sample-and-hold amplifiers. Quantizers and other signal processors generate digital signal output by sampling and digitizing the integrated voltage output of the current integrator.

Abstract: A disposable micro-prism test chip for surface plasmon resonance measurement comprises a micro-tray and a micro-prism mounted on the micro-tray. The micro-tray and the micro-prism form at least one cell for providing a fluid dielectric medium for measurement. The disposable micro-prism test chip also comprises a thin metal layer coated on the surface of the micro-prism in the formed cell between the fluid dielectric medium and the micro-prism. The micro-tray may have at least one through window for forming the at least one cell. The micro-tray may also have a half-through cavity facing the micro-prism. The disposable micro-prism test chip is disposed after at least one use. The micro-prism may be fabricated by pulling a heated preform, where the preform has the same cross-section as that of the pulled micro-prism.

Abstract: The present invention includes a high-speed, high-saturation power detector (e.g., a photodiode) compatible with a relatively simple monolithic integration process. In particular embodiments, the photodiode includes an intrinsic bulk absorption region, which is grown above a main waveguide core including a number of quantum wells (QWs) that are used as the active region of a phase modulator. The invention also includes methods of fabricating integrated photodiode and waveguide assemblies using a monolithic, simplified process.

Abstract: A controllable opto-electronic time stretcher comprising a first wave guide and a second waveguide coupled to the first waveguide along a coupling portion; wherein at least one of the first and second waveguides in the coupling portion has a controllable refractive index.

Abstract: The present invention is directed to an apparatus, method and software product for enhancing the dynamic range of a CCD sensor without substantially increasing the noise. Initially, the area of a N×M pixel CCD sensor array is subdivided into two regions, a large region having (M?a) pixels in each column for outputting large-amplitude signals with low noise and a smaller region having a pixels in each column for outputting small-amplitude signals with improved dynamic range. At integration time, the CCD is read out one region's rows at a time into the horizontal shift registers by shifting the pixel charges in either a or M?a vertical shifts. The charges in the horizontal shift registers are then shifted out of the horizontal shift registers in N horizontal shifts. Next, the remaining pixels in the region of the CCD are read out into the horizontal shift registers by shifting the pixel charges in the other of a or M?a vertical shifts.

Abstract: A photonic processor can include a first input for a phase-modulated optical pulse signal, a second input for an optical reference signal, and a plurality of states. Each stage is configured to receive the phase-modulated optical pulse signal and a phase-delayed version of the optical reference signal. The phase-delayed version is phase-delayed in accordance with a phase position of the stage. Each stage is comprised of a reference path, a signal path, a coupler and a balanced photo detector. The coupler receives the phase-modulated optical pulse signal and provides as stage phase-modulated optical pulse signal to the signal path. The signal path is coupled to a first input of the balanced photo detector. The coupler also receives the phase-delayed version and provides a stage optical reference signal to the reference path. The reference path is coupled to a second input of the detector. The detector provides an electronic output signal corresponding to a phase relationship.

Abstract: A time-interleaved analog-to-digital converter for conversion of L analog input signals to L corresponding digital output signals comprises an array of N (N>L) constituent analog-to-digital converters each having an analog input and a digital output and each adapted to digitize an analog input sample, and a controller adapted to (for each of the L analog input signals indexed by i=1, 2, . . . , L) select a number Ni, of constituent analog-to-digital converters from the array of N constituent analog-to-digital converters (wherein Ni?1 and ?i=1L Ni?N), and cause each sample of the analog input signal to be digitized in a respective one of the selected Ni, constituent analog-to-digital converters. The analog-to-digital converter also comprises a multiplexer adapted to (for each of the L analog input signals) multiplex the digitized samples of each of the selected Ni constituent analog-to-digital converters to produce the digital output signal.

Abstract: An interference cancellation system (ICS) may be used with a communication system to prevent or minimize interference from one or more sources. The ICS may receive radio frequency (RF) signals comprised of one or more signals of interest (SOI) and multiple interfering signals. An interference estimation processor (IEP) may be used to estimate the one or more interfering signals. The interfering signals may be estimated using spatial and/or time diversity, which may be combined with statistical methods. The estimated interfering signals may be sent to the ICS, which may use the estimated interference signal to cancel the interference and output the SOI.

Abstract: An improved light to frequency converter optical sensor and method using electronic bias. Adjustable gain also may be provided. A summing circuit sums electrical current from a photo detector and electrical current from a bias current circuit and provides the summed current to an integrator. A threshold detector comparator circuit has an input coupled to the output of the integrator and an output providing a series of pulses. The series of pulses has a frequency based on the light received by the photo detector and the electrical current from the bias current circuit.

Abstract: A photonic analog-to-digital converter is provided that includes a tunable light source, an optical sampling clock source, an optical splitter and a plurality of optical signal processing channels. The tunable light source produces an optical signal at a variable wavelength corresponding to analog levels of an electrical input signal. The optical sampling clock source produces an optical sampling clock signal that defines a sequence of sampling periods. The optical splitter is operably coupled to the tunable light source. The optical splitter splits the optical signal produced by the tunable light source for supply to the plurality of optical signal processing channels. Each one of the optical signal processing channels includes a photonic filter and corresponding optoelectronic thyristor comparator that is operably coupled to the optical sampling clock source.

Abstract: A method of and system of processing a phase-modulated optical signal includes performing, by demodulators, demodulation of the phase-modulated optical signal and outputting optical demodulated signals. The processing further includes performing, by pairs of gated photo detectors respectively connected to the I/Q demodulators, photo detection of the demodulated signals. The processing further tracks and holds electronicversions of the demodulated signals with a track and hold amplifier.

Abstract: An optical analog to digital converter including a light source, a driver, an array of single photon avalanche diodes, and control circuitry. The light source emits photons. The driver receives an analog input signal and to drive the light source on the basis of the analog input signal. The array of single photon avalanche diodes detects the photons provided by the light source. The control circuitry is coupled to the array of single photon avalanche diodes and activates the array of single photon avalanche diodes for a predetermined time interval such that the array of single photon avalanche diodes detects the photons provided by the light source during the predetermined time interval. The control circuitry further determines the number of single photon avalanche diodes of the array of single photon avalanche diodes which detected a photon during the predetermined time interval.

Abstract: A photonic processor can include a first input for an amplitude-modulated optical pulse signal, a second input for an optical reference signal, and a plurality of stages. Each stage is configured to receive the amplitude-modulated optical pulse signal and a version of the optical reference signal. The version is amplitude attenuated in accordance with a position of the stage. Each stage is comprised of a reference path, a signal path, two couplers and a balanced photo detector. The first coupler receives the pulse signal and provides as stage pulse signal to the signal path coupled to a first input of the detector. The second coupler receives the version and provides a stage optical reference signal to the reference path coupled to a second input of the detector. The detector provides an electronic output signal corresponding to an amplitude relationship.

Abstract: A method of sampling a radio frequency signal comprises: receiving the radio frequency signal; modulating an optical signal with the radio frequency signal and an oscillator signal to generate a modulated signal; applying a filter to the modulated signal to generate an intermediate frequency signal, the filter having an intermediate pass band and an intermediate roll-off, the intermediate pass band and the intermediate roll-off in combination defining a intermediate frequency band having a first bandwidth; and sampling the intermediate frequency signal at a sampling frequency using a number of optically interleaved analog-to-digital converters. The oscillator signal and the sampling frequency in combination are arranged such that the intermediate frequency band is defined between consecutive multiples of half of the sampling frequency. Corresponding apparatus for sampling a radio frequency signal is also disclosed.

Abstract: An optical A/D converter according to the present invention includes an optical splitter that splits an analog input signal light into plurals, a plurality of Mach-Zehnder interferometers to which each of the signal lights split by the optical splitter is input, and plurality of optical/electrical conversion unit that convert each signal lights output from each Mach-Zehnder interferometer into a digital electrical signal, in which each Mach-Zehnder interferometer includes optical intensity-to-phase conversion unit that optically convert intensity of the input signal light into an amount of phase shift and the amount of phase shift differs for each Mach-Zehnder interferometer. Then, it is possible to provide a high speed and low power consuming optical demodulation circuit.

Abstract: A digital/analog converter (30) with a first return-to-zero unit (311) which is connected to a first busbar (321), wherein the first busbar (321) is connected in each case to a first output of several differential units (351, 352, 35n). In this context, the first return-to-zero unit (311) provides at least one clock input which is directly or indirectly connected to a first photodiode, wherein the first photodiode is fed from a pulsed light source (5).