Abstract: There is presented optical interferometer apparatus for generating at least a first and a second state for each of at least two different quantum cryptographic basis sets and associated methods for operating the apparatus. First and a second interferometer arm paths and at least two interferometer output paths are provided. Each of the first and second interferometer arm paths; and the first and second optical output paths comprises a controllable phase modulator for controllably changing the phase of light propagating along the respective paths. This maybe a silicon carrier depletion phase modulator. The output from the controllable phase modulators of the first and second optical output paths are used together for defining each of the first and second states for each respective basis set. In some examples at least one of the interferometer arm paths comprises a further controllable phase modulator such as a thermo-optic phase modulator.

Abstract: A frequency offset processing method, apparatus, and a storage medium, where the method includes: determining a frequency offset of a preset channel in a wavelength selective switch (WSS); determining a correspondence between a frequency offset and a wavelength or a correspondence between a frequency offset and a pixel position based on the frequency offset of the preset channel; and determining a frequency offset of a traffic channel according to the determined correspondence.

Abstract: A direct-detection optical data receiver capable of low-latency SSBI cancellation using one or more FIR filters in the chain of digital signal processing thereof. In an example embodiment, a DSP of the receiver may have first and second serially connected FIR filters whose filter coefficients are updated based on a same feedback signal. An SSBI-cancellation circuit of the DSP is configured to estimate the SSBI by summing a scaled square of the filtered signal generated by the first FIR filter and a scaled square of the filtered signal generated by the second FIR filter. In some embodiments, the SSBI-cancellation circuit may have two or more serially connected stages, each of which incrementally improves the accuracy of the SSBI estimate. In some embodiments, the need for dedicated and/or specialized filter-calibration procedures may beneficially be circumvented.

Abstract: A transmission device includes: a first wavelength conversion circuit configured to convert a wavelength band of a wavelength multiplexed signal light based on a wavelength of a second excitation light by performing four-wave mixing on the second excitation light and the wavelength multiplexed signal light inputted to a second nonlinear medium; and a second wavelength conversion circuit configured to convert the wavelength band of the wavelength multiplexed signal light based on a difference between frequencies of a third excitation light and a fourth excitation light by performing four-wave mixing on the third excitation light and the fourth excitation light and the wavelength multiplexed signal light inputted to a third nonlinear medium.

Abstract: Measurement of entangled photon quantum wavefunction properties is vital for studying the fundamentals of entanglement and for future applications in quantum communications, quantum metrology, quantum sensing and imaging. Despite its importance, measuring the wavefunction is difficult, particularly in pulsed and other systems with system features and wavefunctions changing in space and time. This invention uses ghost imaging techniques to directly measure the entangled photon wavefunction of pulsed origin temporal and polarization entangled photons. The invention may be used to improve wavefunction quality after propagation through turbulent or scattering media.

Abstract: Disclosed herein are embodiments of an aerial network system including a first transceiver configured to transmit and receive free space optical (FSO) signals and a second transceiver configured to transmit and receive radio frequency (RF) signals. A processor provides modulated data signals to the first and second transceivers for transmission and receives demodulated signals from the first and second transceiver. The processor is configured for policy-based multipath admission of requests for access to an IP-routing enabled overlay network. The processor includes an inverse mission planning system configured for predictive traffic load balancing of transmitted FSO signals and RF signals. The inverse mission planning system includes radio behavior models and aerial platform models, and is configured for geographic simulation and optimization of mission planning data based upon user-inputted mission-specific data.

Abstract: A coherent receiver performing coherent detection on polarization multiplex light into which first polarization light and second polarization light are multiplexed, and splitting the polarization multiplex light into the first polarization light and the second polarization light, an adaptive equalizer compensating the waveform distortion of a signal superimposed onto the first polarization light by using a first FIR filter, compensating the waveform distortion of a signal superimposed onto the second polarization light by using a second FIR filter, and by decoding each of the signals whose waveform distortion has been compensated, generating their respective decoded data, an error ratio calculator calculating the bit error ratio of each decoded data generated by the adaptive equalizer, a margin calculator calculating a margin from the bit error ratio of an error correction limit in each bit error ratio calculated by the error ratio calculator, and a tap number controller setting up the numbers of taps of the

Abstract: Provided is a free-space optical signal alignment and transmission device, system, and method. The alignment and transmission device includes an optical engine and a collimating lens module which are connected. The optical engine converts an electrical signal into an optical signal and includes a base board, and a laser driver chip, a laser, a lens array module, a photodiode, and an electrical signal amplifier chip that are provided on the base board; the collimating lens module collimates and sends the optical signal transmitted from the optical engine to free space for transmission, and further shapes and sends the optical signal received from the free space to the optical engine. The laser is connected to the laser driver chip and the lens array module. One end of the photodiode is connected to the lens array module, and the other end thereof is connected to the electrical signal amplifier chip.

Abstract: [Problem] A method, a device, a system and a program that can adjust the drive timing of a photon detector with high speed and high reliability is provided.

Abstract: Systems and methods for constellation shaping using low rate loss bit-level distribution matchers include receiving blocks of input bits and, for each input block of a predetermined size, assigning a respective codeword of a predetermined output block size. The number of bits of a given bit value in the codeword is dependent on a predetermined target probability distribution. A one-to-one mapping exists between each possible combination of input bits and a codeword for input blocks containing the combination. Some codewords include a number of bits having the given bit value that is different than the predetermined target probability distribution, but an average number of bits having the given bit value in the available codewords meets the predetermined target probability distribution. The disclosed methods result in more available codewords and a lower rate loss than in bit-level distribution matchers with a constant modulus, while achieving similar shaping.

Abstract: High-channel-count optical transceivers can be implemented in photonic integrated circuits (PICs) with shared lasers, splitting the light of each laser between multiple lanes prior to modulation. To reduce waveguide crossings in such PICs, transmitter and self-test functionality may be distributed between separate device layers. Various beneficial transmitter circuitry layouts are disclosed.

Abstract: A communication device used in an optical communication system, the communication device includes a mode change over device configured to switch between a learning mode for learning a normal state of an optical transmission path before operation and a monitoring mode for monitoring a state of the optical transmission path during operation, an anomaly detector configured to detect an anomaly of the optical transmission path using a prediction model determined by the learning mode when the monitoring mode is selected, and a data writer configured to extract waveform data including information related to the anomaly to output the extracted waveform data to an outside when the anomaly is detected.

Abstract: Methods and systems for a distributed optical transmitter with local domain splitting are disclosed and may include, in an optical modulator integrated in a silicon photonics chip: receiving electrical signals, communicating the electrical signals to domain splitters along a length of waveguides of the optical modulator via one or more delay lines, and generating electrical signals in voltage domains utilizing the domain splitters for modulating the optical signals in the waveguides of the optical modulator by driving diodes with the electrical signals generated in the voltage domains. The delay lines may comprise one delay element per domain splitter, or may comprise a delay element per domain splitter for a first subset of the domain splitters and more than one delay element per domain splitter for a second subset of the domain splitters.

Abstract: A transmitter optical subassembly is disclosed including a substrate and a direct modulated laser disposed on the substrate. A single-stage isolator, a polarization direction rotator, and an optical branching filter are disposed side by side on the substrate in a light propagation direction. The polarization direction rotator can adjust linearly polarized light to P-polarized light, the optical branching filter includes an optical splitter subassembly and a filter subassembly, and an optical splitter film in the optical splitter subassembly is an optical splitter film with P polarization. The polarization direction rotator adjusts the incident linearly polarized light to the P-polarized light, and the optical splitter film in the optical branching filter is the optical splitter film with P polarization; all P-polarized light with single polarization can pass through the optical branching filter, without causing any polarization loss or two peaks.

Abstract: The present application provides a method and a device for synchronizing a high-speed quantum key generation system, wherein the method comprises: a sender aligns first light pulse of signal light with that of synchronization light, and controls the signal light not to emit light during N consecutive periods within each period Tt of the synchronization light; a receiver performs time measurement on received signal light pulse, the signal light emits light at the remaining corresponding positions except the N consecutive non-emitting positions in each period Tt, the emitting positions can join the statistical process of T1i and T2i, the statistical time is reduced by several orders of magnitude relative to the existing method of only sending single signal light pulse, and the statistical process can be completed in a few hundred milliseconds or even shorter.

Abstract: An optically biased photonic link receives a radio frequency (RF) signal and includes a signal laser joined to an optical intensity modulator. A low noise amplifier receives the RF signal and provides an amplified signal to the modulator. The modulator converts the signal into an optical signal. The amplifier and modulator are powered by a photovoltaic array. The array receives power from a remotely located power laser. The optical signal is received by a link receiver which provides an analysis signal and an output signal. A bias logic circuit uses the analysis signal to provide an optical bias signal to an optical detector joined to modulator. The optical detector provides a responsive bias voltage to the modulator.

Abstract: A method for assigning spectral resources comprises assigning spectral resources for a plurality of communication channels. The spectral resources for the plurality of communication channels comprise excess resources that are at least tentatively kept unoccupied. The excess resources of a plurality of communication channels are assigned to be spectrally contiguous.

Abstract: An automatic bias control circuit for an optical modulator using nested MZIs includes: a parent MZI control bias voltage generator that generates a parent MZI control bias voltage; a photodetector that converts tapped output light from the optical modulator into an electrical signal; a low-frequency cut-off circuit that suppresses modulation components that are slower than a first frequency, included in the electrical signal; and a control unit that controls the parent MZI control bias voltage generator on the basis of an electrical signal in which the slower modulation components have been suppressed. The control unit controls the parent MZI control bias voltage generator so as to minimize the effective value or the peak value of the electrical signal in which the slower modulation components have been suppressed.

Abstract: Systems and methods for performing operations based on LIDAR communications are described. An example device may include one or more processors and a memory coupled to the one or more processors. The memory includes instructions that, when executed by the one or more processors, cause the device to receive data associated with a modulated optical signal emitted by a transmitter of a first LIDAR device and received by a receiver of a second LIDAR device coupled to a vehicle and the device, generate a rendering of an environment of the vehicle based on information from one or more LIDAR devices coupled to the vehicle, and update the rendering based on the received data. Updating the rendering includes updating an object rendering of an object in the environment of the vehicle. The instructions further cause the device to provide the updated rendering for display on a display coupled to the vehicle.

Abstract: A wavelength selective switch (WSS) apparatus. The WSS apparatus includes: a plurality of input/output port groups; a plurality of switching lens parts; a plurality of wedge prism parts; a beam expansion part; a wavelength dispersion part; a path combining part configured to combine the groups of the plurality of light beams transmitted from the switching lens parts on the dispersion axis; an imaging optic part; and a switching unit including a plurality of surface areas corresponding to the plurality of input/output port groups, the switching unit being configured to angular displace an angle of a selected wavelength on the switching axis such that the wavelength selected from multiple wavelength channels of an input port selected independently for each of the plurality of input/output port groups is transmitted to an output port of the plurality of input/output port groups selected independently.