Abstract: A radio frequency generator has first and second lasers configured to emit first and second optical outputs; a reference module configured to receive at least part of the first and second optical outputs from the first and second lasers; a control module connected to the first and second lasers and to the reference module; and an optical-to-electrical (O/E) converter configured to process optical signals, originating from the first and second single-frequency lasers, to provide a radio frequency output. Another radio frequency generator has a control module; and a reference module connected to the control module. The reference module includes a photonic integrated circuit (PIC) having first and second single-frequency lasers configured to emit first and second optical outputs; an unbalanced Mach-Zehnder interferometer (UMZI) with first and second 3×3 optical splitter/combiners; first and second peripheral splitter/combiners; and an output splitter/combiner.

Abstract: A control signal may be modulated on an optical wave. A transmitter may transmit the control signal to a switch/processor location. At the remote node, the control signal is received and converted from an optical signal to an electrical signal to drive the switch/processor. To provide electrical power at the switch/processor location, optical power is transmitted from a distance and converted to electrical power using a series of PDs. Monitoring tones may be sent to the remote node and fed back to the transmitter to realize an operation state and detect a bias drift. Accordingly, an OSP function at a remote node is enabled without using any local electrical power supply.

Abstract: An optical wireless communications receiver for a portable communications device, the receiver being configured to receive radiation signals on which communication data is encoded, wherein the receiver is comprised in or on or configured for mounting to at least part of a periphery or edge of the device. Advantageously, the optical wireless communications comprises a plurality of, receiver elements distributed along or around the receiver and/or comprises an optical guide configured to receive radiation and convey at least part of the radiation along the optical guide to at least one of the receiver elements.

Abstract: A light emitting diode may include a light emission layer and a charge transport layer disposed on the light emission layer. A grating including a plurality of nanoholes may be formed by removing a portion of the charge transport layer and/or the light emission layer and depositing a plasmonic metamaterial on a remaining portion of the charge transport layer and/or the light emission layer. The nanoholes may include the plasmonic metamaterial deposited inside the recesses formed by the remaining portion of the charge transport layer and/or the light emission layer, with an additional portion of the charge transport layer disposed on top. A pitch, diameter, and/or depth of the nanoholes may be configured to maximize the quantum efficiency of the light emitting diode, especially at a microscale of less than 100 microns.

Abstract: A packaged optical receiver, comprising: a photodiode configured to receive an optical signal; a transimpedance amplifier (TIA) coupled to the photodiode; and a signal pin; wherein the optical receiver is configured to receive, via the signal pin, a reset signal; and wherein the optical receiver is configured to output in response to the reset signal, via the signal pin, a received signal strength indication (RSSI) for the received optical signal.

Abstract: An optical receiver, e.g., for an Optical Supervisory Channel (OSC), whose optical front end comprises a polarization-diversity coherent optical receiver configured to receive a conventional intensity-modulated (e.g., OSC) signal. Four quadrature components of the received OSC signal detected by the polarization-diversity coherent optical receiver are sampled at a relatively high sampling rate and are used to calculate the Stokes parameters of the OSC signal. As a result, the Stokes parameters can be updated at the high sampling rate, which can be suitably selected to enable polarization tracking with a relatively high time resolution and/or at relatively high SOP-rotation speeds. The four detected quadrature components are appropriately combined in the receiver DSP to determine the intensity of the received OSC signal, which is then used in a conventional manner to recover the OSC data encoded therein.

Abstract: An on-chip adaptive optical receiver system, an optical chip, and a communication device are disclosed, which are applied to optical communication. The on-chip adaptive optical receiver system includes an antenna array configured for separating received spatial light to obtain a plurality of sub-light spots; an optical phased array configured for performing phase-shifting processing and beam combining processing on the sub-light spots to obtain combined light; and an optical receiving module configured for demultiplexing the combined light to obtain beacon light. The optical receiving module is further configured for detecting intensity information of the beacon light and generating a feedback signal according to the intensity information.

Abstract: A method for allocating bandwidth to a first ONU, a second ONU, M1 ONUs, and M2 ONUs includes, during an allocation cycle, (i) granting a respective upstream time slot to, of a plurality of N ONUs, only each of the M1 ONUs, and (ii) granting a first upstream time slot to the first ONU. Each of the M1 ONUs and M2 ONUs is one of the plurality of N ONUs. The method also includes, during a subsequent cycle, (i) granting a respective upstream time slot to, of the plurality of N ONUs, only each of the M2 ONUs. The N ONUs includes a skipped-ONU that is one of either, and not both, the M1 ONUs and the M2 ONUs. The method includes, during the subsequent allocation cycle, granting a second upstream time slot to a second ONU, which is not one of the plurality of N ONUs.

Abstract: An eye diagram measuring method includes: sampling a compensated input signal according to a reference voltage and a reference clock to obtain a first sampling result; and sampling a to-be-compensated input signal according to a scan voltage and a scan clock to obtain a second sampling result, including: (b1) storing a minimum phase and a voltage level which render the first sampling result identical to the second sampling result; (b2) increasing the voltage level and repeating operation (b1); (b3) decreasing the voltage level and repeating operation (b1); (b4) storing a maximum phase and the voltage level which render the first sampling result identical to the second sampling result; (b5) increasing the voltage level and repeating operation (b4); and (b6) decreasing the voltage level and repeating operation (b4). Voltage levels, maximum phases and minimum phases that are stored are for adjusting the reference voltage and the reference clock.

Abstract: An optical sensor having a common light sensing circuit for synchronously sensing a plurality of color light signals is provided. A plurality of photoelectric components respectively convert the plurality of color light signals into a plurality of photocurrents. A plurality of gain amplifiers respectively multiply the plurality of photocurrents by a plurality of gains to output a plurality of amplified photocurrents. An arithmetic circuit adds up the plurality of amplified photocurrents to output a total amplified photocurrent signal. A common analog-to-digital converter converts the total amplified photocurrent signal into a digital signal. A counter circuit counts bit values of the digital signal to output a counting signal.

Abstract: A method for signal reconstruction, the method may include obtaining, an input digital signal that is a digital representation of an received optical signal, wherein the received optical signal represents a transmitted optical signal that was transmitted by a coherent transmitter and over a channel to a coherent optical receiver; wherein a phase difference between the transmitted optical signal and the received optical signal is unknown; and generating a hybrid estimation, wherein the hybrid estimation represents a magnitude of the transmitted optical signal and a phase of the received optical signal.

Abstract: Methods, systems, and devices for wireless communications are described. Techniques described herein provide for managing peak-to-average power ratio (PAPR) using an index modulation scheme. A first communication device may generate a set of information bits to convey to a second communication device via the index modulation scheme. A set of extra information bits may be generated using a linear coding scheme, and the set of extra information bits may be inserted into the set of information bits. The first communication device may encode the set of information bits with the inserted extra, and the first communication device may transmit, to the second communication device, a signal including the encoded set of information bits.

Abstract: A coordinate calibrating method includes the steps of: (1) reading paper coordinates by adopting two OID sensors, comparing the coordinates read by the two OID sensors with pre-designed coordinates of paper to obtain coordinate deviation of positions of the two OID sensors, and according to the coordinate deviation, calculating an inclination angle value ? generated by the coordinates of the two OID sensors; and (2) according to the coordinate deviation and the inclination angle value, calibrating an actually read coordinate position of a pen by selecting the second OID sensor as a reference point, translating horizontally and vertically coordinates of the pen to be corrected first, and then rotating the coordinates by the angle ? with reference to the second OID sensor, so that the positions of the two OID sensors coincide with pre-designed standard positions, and the coordinate position of the pen is calibrated.

Abstract: A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter.

Abstract: A semiconductor device comprises a semiconductor die and an integrated capacitor formed over the semiconductor die. The integrated capacitor is configured to receive a high voltage signal. A transimpedance amplifier is formed in the semiconductor die. An avalanche photodiode is disposed over or adjacent to the semiconductor die. The integrated capacitor is coupled between the avalanche photodiode and a ground node. A resistor is coupled between a high voltage input and the avalanche photodiode. The resistor is an integrated passive device (IPD) formed over the semiconductor die. A first terminal of the integrated capacitor is coupled to a ground voltage node. A second terminal of the integrated capacitor is coupled to a voltage greater than 20 volts. The integrated capacitor comprises a plurality of interdigitated fingers in one embodiment. In another embodiment, the integrated capacitor comprises a plurality of vertically aligned plates.

Abstract: A bandwidth scheduling method includes receiving a bandwidth request sent by a data center, where the bandwidth request includes bandwidth required to transmit non-real-time traffic; allocating, based on historical bandwidth information, the bandwidth required by the data center to transmit the non-real-time traffic in a future time period, where the historical bandwidth information is used to predict occupation of total bandwidth by the data center in a region in which the data center is located at each moment in the future time period; and sending a bandwidth response to the data center, where the bandwidth response includes an allocation result.

Abstract: A method of equalising optical losses, at a required operating wavelength, in waveguide sections in an optoelectronic device comprising a first semiconductor waveguide section and a second semiconductor waveguide section, the method comprising determining (1301) a first optical loss through the first waveguide section for a signal with the required operating wavelength, determining (1302) a second optical loss through the second waveguide section for the signal, determining (1303) a loss difference between the first optical loss and the second optical loss, determining (1304) a first bias voltage based on the loss difference and the operating wavelength, such that the loss difference is reduced, and applying (1305) the bias voltage to the first waveguide section.

Abstract: An optical reception device including: a local light transmission unit configured to generate a plurality of local lights having different wavelengths, select a local light having a wavelength that is close to the wavelength of a received optical signal from among the plurality of generated local lights having different wavelengths, and transmit the selected local light to a coherent receiver; a demultiplexing unit configured to demultiplex a received optical signal and transmit the demultiplexed optical signal to the coherent receiver via a first path; and a wavelength detection unit configured to input the optical signal demultiplexed by the demultiplexing unit via a second path, split the input optical signal into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and output, to the local light transmission unit, a control signal for causing the local light transmission unit to output a local light having a frequency that corresponds to a path in which the optical sig

Abstract: The purpose of the present invention is to improve signal modulation resolution. A coarse phase modulation element 62A modulates a signal into any of M1 (M1 is an arbitrary integer) patterns in a first range. Fine phase modulation elements 62B-1 through 62B-(k?1) respectively modulate the signal into any of M2 through Mk (M2 through Mk are arbitrary integers that are independent of each other and M1) patterns in a second range through k-th range (k is an integer of 2 or greater). A coarse DAC 61A and DACs 61B-1 through 61B-(k?1) perform control such that the second range through k-th range become narrower than the first range.

Abstract: An optical transmitter generates symbols for transmission by applying a predetermined coding method to each of m-valued transmission symbols generated from transmission data, generates signal light by performing optical modulation on the basis of the symbols for transmission, and transmits the signal light. An optical receiver generates a series of digital signals from the received signal light, detects coded symbols by applying predetermined digital signal processing to the series of digital signals, decodes the m-valued transmission symbols from the detected coded symbols, and restores the transmission data from the decoded m-valued transmission symbols.

Abstract: Systems and methods for an optical ternary content addressable memory (TCAM) are provided. The optical TCAM implements a time-division multiplexing (TDM) based encoding scheme to encode each bit position of a search word in the time domain. Each bit position is associated with at least two time slots. The encoded optical signal comprising the search word is routed through one or more modulators configured to represent a respective TCAM stored word. If a mismatch between at least one bit position of the search word and at least one TCAM stored word occurs, a photodetector or photodetector array will detect light.

Abstract: A packaged integrated white light source configured for illumination and communication or sensing comprises one or more laser diode devices. An output facet configured on the laser diode device outputs a laser beam of first electromagnetic radiation with a first peak wavelength. The first wavelength from the laser diode provides at least a first carrier channel for a data or sensing signal.

Abstract: A method in an electronic device, the method includes projecting infrared (“IR”) light from a plurality of light emitting diodes (“LEDs”) disposed proximate to the perimeter of the electronic device, detecting, by a sensor, IR light originating from at least two of the plurality of LEDs reflected from off of a person, and carrying out a function based on the relative strength of the detected IR light from the LEDs.

Abstract: A transimpedance amplifier includes a feedback circuit that generates a bypass current in accordance with a charging voltage of a capacitor based on a difference between a voltage signal and a reference voltage signal, a differential amplifier circuit that generates a differential signal in accordance with the difference between the voltage signal and the reference voltage signal, and a detector circuit that resets the charging voltage of the capacitor in response to a detection of end of a burst optical signal. The feedback circuit detects start of the burst optical signal based on the charging voltage, maintains a time constant at a first time constant for a predetermined period from the detection of the start of the burst optical signal, and, upon an elapse of the predetermined period, switches the time constant from the first time constant to a second time constant larger than the first time constant.

Abstract: The present invention is directed to communication systems and methods. According to a specific embodiment, FEC data streams from multiple FEC data lanes are received. First stage interleaving and inner encoding are performed on the FEC data streams to generate inner encoded data streams. A second stage interleaving process is performed to interleave the inner encoded data streams. There are other embodiments as well.

Abstract: A negative feedback inductor and a gate inductor are formed in different wiring layers of a substrate so as to be at least partially overlapped with each other in a plan view. When the lower wiring layer is thinner and the upper wiring layer is thicker, the negative feedback inductor Lc is formed in the lower wiring layer that is thinner.

Abstract: The application provides an optical network apparatus and an optical module. The optical network apparatus is configured to: convert, by a processing chip, the received N electrical signals from a board interface chip into a first electrical signal and a second electrical signal; and send the above two electrical signals to a first optical transmission component and a second optical transmission component, respectively; convert, by the first optical transmission component, the first electrical signal into a first optical signal; and convert, by the second optical transmission component, the second electrical signal into a second optical signal. The N to-be-sent electrical signals are combined, and only two optical transmission components are connected to the processing chip. Therefore, the processing chip does not need to be connected to four optical transmission components, fewer optical transmission components are required, and costs are reduced.

Abstract: Optical network devices, optical receivers, Automatic Gain Control (AGC) circuits, and power detection systems are provided for detecting power of optical signals within an optical communication system. An optical network device, according to one implementation, includes a receiver configured to receive an optical signal. The optical network device also includes a low bandwidth path configured to detect a low-band power component of the optical signal within a channel of interest and a broad bandwidth path arranged in parallel with the low bandwidth path. The broad bandwidth path is configured to detect a broad-band power component of the optical signal within broad-band channels including at least the channel of interest. A power detection output is derived from the low-band power component and the broad-band power component.

Abstract: In one embodiment, stable and controlled circuit element biasing is provided in a circuit comprising a voltage source operable to output a first voltage, a reference voltage source operable to output a reference voltage, a circuit element biased, during operation, by the first voltage at a first end and by a second voltage at a second end, a voltage controller coupled to the second end of the circuit element, wherein the voltage controller is operable to adjust the second voltage based on a gain output, a gain controller operable to receive the reference voltage as a first input and the second voltage as a second input, wherein the gain controller is operable to generate, at an output of the gain controller, the gain output based on the second voltage and the reference voltage, and a feedback loop that extends from the output of the gain controller, through the voltage controller, and to the second input.

Abstract: A method and apparatus for the increase of internal data throughput and processing capability for SSD's, to enable processing of database commands on an SSD. A front-end ASIC is provided with 256 to 512 RISC processing cores to enable decomposition and parallelization of host commands to front-end module (FM) ASICs that each in turn are coupled to multiple NVM dies, as well as processing of host database operations such as insert, select, update, and delete. Each FM ASIC is architected to increase parity bits to 33.3% of NVM data, and process parity data with 14 LDPC's. By increasing the parity bits to 33.3%, BER is reduced, power consumption is reduced, and data throughput within the SSD is increased.

Abstract: A light-emitting device includes a laser unit; and a first capacitive element and a second capacitive element that supply a driving electric current to the laser unit; wherein the first capacitive element has smaller equivalent series inductance than the second capacitive element, and the second capacitive element has a larger capacity and a smaller mount area than the first capacitive element.

Abstract: A method includes determining a first power level by performing a first series of measurements based on a first series of burst transmissions from an optical transmitter of an optical network unit (ONU) in an optical network. Bursts in the first series of burst transmissions include a first modified preamble. A second power level is determined by performing a second series of measurements based on a second series of optical burst transmissions. Bursts in the second series of burst transmissions include a second modified preamble. A first power level (P0) and a second power level (P1) are determined based on the first power level and the second power level and one or more additional parameters associated with transmissions from the optical transmitter are determined based on P0 and P1. Based on the additional parameters, it is determined whether the optical transmitter complies with specifications of the optical network.

Abstract: A clock data recovery circuit detects illegal decisions for received data, accumulates a phase gradient for the data, determines a number of the illegal decisions in a configured window for receiving the data, and if the number of the illegal decisions exceeds a pre-defend number in the window, applies a sum of the accumulated phase gradient and a phase increment having a sign of the accumulated phase gradient to a clock circuit for the data receiver.

Abstract: A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter.

Abstract: A semiconductor device comprises a semiconductor die and an integrated capacitor formed over the semiconductor die. The integrated capacitor is configured to receive a high voltage signal. A transimpedance amplifier is formed in the semiconductor die. An avalanche photodiode is disposed over or adjacent to the semiconductor die. The integrated capacitor is coupled between the avalanche photodiode and a ground node. A resistor is coupled between a high voltage input and the avalanche photodiode. The resistor is an integrated passive device (IPD) formed over the semiconductor die. A first terminal of the integrated capacitor is coupled to a ground voltage node. A second terminal of the integrated capacitor is coupled to a voltage greater than 20 volts. The integrated capacitor comprises a plurality of interdigitated fingers in one embodiment. In another embodiment, the integrated capacitor comprises a plurality of vertically aligned plates.

Abstract: Examples described herein relate to an analog front-end (AFE). The AFE includes a trans-impedance amplifier to receive an input current and generate a pair of the differential voltage signals based on the input current and a reference current. Further, the AFE includes a dynamic voltage slicer to receive the differential voltage signals at input terminals and supply digital voltages at output terminals. The dynamic voltage slicer includes a preamplifier to generate a pair of intermediate voltages based on the differential voltage signals sampled at a predetermined frequency. The dynamic voltage slicer also includes a voltage latch circuit coupled to the preamplifier, wherein the voltage latch circuit is to regenerate a pair of digital voltages based on the pair of the intermediate voltages. Moreover, the AFE includes a logic latch coupled to the dynamic voltage slicer to provide digital output states based on the pair of the digital voltages.

Abstract: Methods and systems for waveguide delay based equalization summing at single-ended to differential converters in optical communication are disclosed and may include: in an photonic circuit including a directional coupler, photodetectors, and a gain stage, receiving an input optical signal; splitting the input optical signal into first and second optical signals using the directional coupler; generating a first current from the first optical signal using a first photodetector; communicating the first voltage to a first input of the gain stage; generating a second current from the second optical signal using a second photodetector; communicating the second voltage to a second input of the gain stage; and generating a differential output voltage based on the first and second currents using the gain stage.

Abstract: A passive continuous-variable quantum key distribution scheme, where Alice splits the output of a thermal source into two spatial modes, measures one locally and transmits the other mode to Bob after applying attenuation. A secure key can be established based on measurements of the two modes without the use of a random number generator or an optical modulator.

Abstract: A quantum receiver for decoding an optical signal includes a beamsplitter for interfering the optical signal with a local-oscillator field to generate a displaced field, and a single-photon detector for detecting the displaced field. The quantum receiver also includes a signal-processing circuit for determining, based on an electrical output of the single-photon detector, a measurement outcome. The signal-processing circuit also determines, based on the measurement outcome and a feed-forward machine-learning model, a next displacement. The quantum receiver also includes at least one modulator for modulating, based on the next displacement, one or both of the optical signal and the local-oscillator field. Like a Dolinar receiver, the quantum receiver implements adaptive measurements to reduce the error probability of the decoded symbol. The use of machine-learning reduces the latency of the signal-processing circuit, thereby increasing the number of measurements that may be performed for each received symbol.

Abstract: A sampling frequency required for symbol timing recovery is made smaller than that of the related art. A receiver 1 performs visible light communication with a transmitter 8. A received signal generating unit 112 measures an intensity of an electrical signal corresponding to an optical signal received from a transmitter 8 at a predetermined time interval to generate a sequence of received signals. A parameter estimation unit 12 uses a distribution of received signals estimated from the sequence of received signals to estimate any one or more parameters of a maximum luminance value, a synchronization shift, and a steady noise level, the one or more parameters including at least the maximum luminance value.

Abstract: A logarithmic power detector includes a power distributor, a first detection circuit, a second detection circuit and an output circuit. The power distributor is used to generate a first power signal and a second power signal according to an input signal. The first detection circuit is used to attenuate the first power signal to generate a first rectified signal, filter the first rectified signal to generate a first low-pass signal, and amplify the first low-pass signal to generate a first amplification current. The second detection circuit is used to attenuate the second power signal to generate a second rectified signal, filter the second rectified signal to generate a second low-pass signal, and amplify the second low-pass signal to generate a second amplification current. The output circuit is used to receive the first amplification current and the second amplification current to generate a converted voltage related to the input signal.

Abstract: Disclosed herein are transimpedance circuits, as well as related methods and devices. In some embodiments, a transimpedance circuit may include a current source bias terminal, a current source output terminal, and a transimpedance amplifier coupled to the current source output terminal, wherein voltage signals at the current source bias terminal are correlated with voltage signals at the current source output terminal. In some embodiments, the current source may be a photodiode.

Abstract: Consistent the present disclosure, a network or system is provided in which a hub or primary node may communication with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity that may be greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed that receive data carrying optical signals from and supply data carrying optical signals to the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, and optical add/drop multiplexer, for example. Consistent with an aspect of the present disclosure, optical subcarriers may be transmitted over such connections. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced.

Abstract: A calibration method of an equalizer circuit for a memory storage device is disclosed. The calibration method includes: receiving a first signal; adjusting, by the equalizer circuit, the first signal according to a control parameter to output a second signal; generating a first sampling signal according to a first reference signal and the second signal, wherein the first sampling signal reflects data transmitted by the first signal; and generating a second sampling signal according to a second reference signal and the second signal and adjusting the control parameter according to the second sampling signal to calibrate the equalizer circuit, wherein a voltage value of the first reference signal is different from a voltage value of the second reference signal.

Abstract: A data acquisition system may include an input for receiving an input signal for the data acquisition system, a plurality of data paths including a first data path and a second data path, and a signal estimator configured to determine a magnitude of the input signal using estimation of the input signal and dynamically deactivate one of the first and second data paths based on the magnitude of the input signal.

Abstract: System and method for fiber-optic time frequency and data joint transmission, comprising local end, relay nodes, and remote end. In each local end, relay node, and remote end, multiplexing and demultiplexing of time frequency signals, optical supervisory signals, and optical communication data services are performed by CWDM modules and OSC-band wavelength multiplexer/demultiplexers, and processing (transmitting, relaying, receiving) is performed by corresponding processing modules for joint transmission. A sub-band of standard OSC band is used for transmitting time frequency signal so that transmission of optical supervisory signal is not influenced while no extra band resource is occupied with improved utilization of wavelength resources and reduced costs.

Abstract: Embodiments herein disclose receiver of coherent optical communication link and method of compensating carrier phase offset in receiver. 90° optical hybrid is configured to receive input of reference optical carrier (LO) signal and modulated optical signal (S) and carrier phase offset detection block is configured to generate output signal representing average of the phase offset at the input of the carrier phase offset detection block. Electronic control unit configured to receive output signals from the carrier phase offset detection block for generating control signals and tunable phase delay block configured to receive the control signals from the electronic control unit. 90° optical hybrid, carrier phase offset detection block, electronic control unit and the tunable phase delay block are configured in feedback loop, such that outputs of the carrier phase offset detection block are used for tuning the phase delay of the tunable phase delay block to achieve carrier phase synchronization.

Abstract: A test system and interface circuitry for antenna-free bit error rate testing of an electronic device under test, including a pulse shaping circuit with a pulse shaping filter circuit to pulse shape a modulating signal before amplitude modulation with a carrier signal, and the amplitude modulated signal is coupled directly or via a transformer and a socket to the device under test without antennas to facilitate automated device testing with simple reconfiguration of signal generators for different device type. A method includes filtering a square wave modulating signal to create a pulse shaped modulating signal, amplitude modulating a carrier signal with the pulse shaped modulating signal to create an amplitude modulated signal, providing the amplitude modulated signal to the socket, and evaluating a bit error rate of the DUT according to receive data from the DUT and according to the BER test transmit data.

Abstract: A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

Abstract: Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, an apparatus includes laser operable to supply an optical signal, a digital signal processor operable to supply digital signals, a digital to analog circuitry operable to provide analog signals based on the digital signals, and driver circuitry is coupled to the digital to analog circuitry and operable to supply at least one drive signal. The apparatus also includes a modulator operable to receive said at least one drive signal, modulate the optical signal based on said at least one drive signal to provide a plurality of optical subcarriers, amplitude modulate the plurality of optical subcarriers at a first frequency to carry first control information, and modulate the plurality of subcarriers at a second frequency to carry second control information.