Abstract: A wireless optical communication network includes a base station established for wireless optical communication using a wireless optical signal and including a participant apparatus moveable with respect to the base station including a communication unit established for wireless optical communication. Further, the participant apparatus includes a deflection unit configured to deflect at least part of the wireless optical signal between a first direction between the deflection unit and the communication unit and a second direction between the deflection unit and the base station.

Abstract: Systems and methods to transmit audio-video signals over an optical communication channel are described. One aspect includes receiving a plurality of audio-video electrical signals at an optical transmitter. The optical transmitter may also receive a plurality of out-of-band electrical signals. The optical transmitter may collectively modulate the audio-video electrical signals to generate a composite electrical signal. In one aspect, the optical transmitter bias current-modulates a bias current level of the composite electrical signal using the electrical out-of-band signals, and generates a modulated electrical signal based on the bias current-modulating. The optical transmitter may convert the modulated electrical signal into a modulated optical signal using a laser diode, and transmit the modulated optical signal to an optical receiver over an optical communication channel.

Abstract: A method and apparatus that cancels or reduces DC offset in a fully-differential optical receiver. The method includes receiving differential optical signals, converting, with photodetectors, the differential optical signals to differential current signals representative of the differential optical signals, converting, using a transimpedance amplifier, the differential current signals to differential intermediate voltage signals, amplifying, using a main amplifier, the differential intermediate voltage signals to generate differential output voltage signals, and cancelling a DC component of the differential output voltage signals using a fully differential DC cancellation circuit. Output offset may also be cancelled or reduced using digital control.

Abstract: A method for operating an optical modulator includes receiving a narrowband radio frequency (“RF”) signal. The method further including, responsive to receiving the narrowband RF signal, modulating the narrowband RF signal using a double sideband suppressed carrier (“DSBSC”) modulation scheme to generate a DSBSC optical signal. The method further including transmitting the DSBSC optical signal to an optical transmitter.

Abstract: A hub node may or have a capacity greater than that of associated leaf nodes. Accordingly, inexpensive leaf nodes may be deployed to 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, each connection including one or more segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator. As the capacity requirements of the leaf nodes change, the number of subcarriers associated with, and thus the amount of data provided to, each node, may be changed accordingly.

Abstract: Device and method for processing an optical signal. The device includes a photonic device arranged between a first input/output and second input/output and optically communicating with the inputs/outputs by a signal path for transmission of an optical signal in a first or second direction between the first input/output and second input/output. The device includes an optical gain element for amplifying the optical signal. The device includes a path switching circuit including a first signal amplification path connectable between the first input/output and the photonic device for optically coupling the signal path to and from the optical gain element, and a second signal amplification path connectable between the photonic device and the second input/output for optically coupling the signal path to and from the optical gain element. The path switching circuit selectively connects the first or second signal amplification path into the signal path.

Abstract: An uplink transmission band and a downlink transmission band that are allocated to each of a plurality of users are determined based on allocation information indicating allocation of a frequency bandwidth available to each of the plurality of users, and are output as uplink transmission band allocation information and downlink transmission band allocation information, respectively. Based on the downlink transmission band allocation information, downlink signals output from a plurality of wireless control devices toward a plurality of wireless devices for each of the plurality of users, and the uplink transmission band allocation information are multiplexed, and the multiplexed signal is demultiplexed into downlink signals for each of the plurality of users and the uplink transmission band allocation information.

Abstract: An optical network component, system, and method are herein described. The system and method include introducing an amplitude modulated (AM) tone and data to an optical modulator generating a modulated optical signal, measuring an amplitude response of the AM tone within the modulated optical signal, calculating a frequency response based on the amplitude response, and calibrating the optical modulator with the frequency response.

Abstract: Disclosed are an optical-time-division-multiplexed transmission method and system using a simple sinusoidally modulated optical signal as an input pulse source. An optical-time-division-multiplexed transmission system comprises: an optical-time-division-multiplexed transmitter by applying a sinusoidal electrical signal, a first multi-level electrical PAM signal, and a second multi-level electrical PAM signal so as to generate an optical-time-division-multiplexed multi-level PAM signal; an optical detector for converting the transmitted optical-time-division-multiplexed PAM signal into an electrical signal; a time-division-demultiplexer for demultiplexing the detected electrical signal into two signals; a MIMO equalizer; and two decision elements for determining the levels of two demultiplexed signals obtained from the MIMO equalizer.

Abstract: An optical network using an optical amplifier in a gain saturation region includes an optical transmission apparatus. The optical transmission apparatus includes an optical transmitter configured to output an optical signal, a semiconductor optical amplifier (SOA) configured to amplify the optical signal outputted through the optical transmitter, and a controller configured to control the SOA to operate in a gain saturation region or a linear gain region depending on whether a forward error correction (FEC) function is used in the optical network.

Abstract: Provided are an apparatus and method of generating a terahertz (THz) signal using a directly-modulated laser. An apparatus of generating a THz signal includes a first directly-modulated laser configured to output a local oscillator (LO) signal, a second directly-modulated laser configured to receive a baseband signal used as data and optically modulate the baseband signal, a band-pass filter configured to filter a spectral component of the baseband signal optically modulated and outputted through the second directly-modulated laser by using a specific frequency bandwidth, a coupler configured to couple the baseband signal filtered through the band-pass filter and the LO signal to each other, and a uni-travelling-carrier photodiode (UTC-PD) configured to generate a THz signal by beating the baseband signal and the LO signal coupled to each other.

Abstract: A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to 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, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. 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: An optical transmission/reception unit includes a carrier rotatable around an axis of rotation, an optical receiver arranged at the carrier on the axis of rotation so as to receive an optical reception signal from a first direction, an optical transmitter arranged at the carrier adjacent to the optical receiver so as to emit an optical transmission signal in a second direction, and a transmission/reception optic arranged at the carrier on the axis of rotation above the optical receiver and extending across the optical receiver and the optical transmitter, wherein the transmission/reception optic includes a reception optic and a transmission optic arranged in the reception optic, wherein the reception optic is configured to guide the optical reception signal striking the transmission/reception optic towards the optical receiver on the axis of rotation.

Abstract: Various example embodiments for supporting supervision in optical communication systems are presented. Various example embodiments for supporting supervision in optical communication systems may be configured to support supervision of an optical path including a remote optically pumped amplifier (ROPA) and, thus, supervision of the ROPA. Various example embodiments for supporting supervision of an optical path including a ROPA may be configured to support supervision of the optical path including the ROPA based on a pair of optical supervisory paths configured to extract a pair of optical supervisory signals from an optical path in a first direction and to insert the pair of optical supervisory signals into an optical path in a second direction. Various example embodiments for supporting supervision of an optical path including a ROPA may be configured to support supervision of the optical path including the ROPA based on a pair of optical time-domain reflectometer (OTDR) paths.

Abstract: Aspects described herein include an optical apparatus comprising a plurality of light-carrying media, a wavelength division multiplexing (WDM) device optically coupled with the plurality of light-carrying media, and a lens arranged between the WDM device and a multicore optical fiber. An arrangement of the plurality of light carrying media and the WDM device are selected to align each of the plurality of light-carrying media with a respective optical core of the multicore optical fiber.

Abstract: A method for phase compensation in an optical communication network includes (1) modifying a modulated signal according to one or more correction factors to generate a compensated signal, to compensate for phase rotation, (2) modulating a magnitude of an optical signal in response to a magnitude of the compensated signal, and (3) modulating a phase of the optical signal, after modulating the magnitude of the optical signal, in response to a phase of the compensated signal.

Abstract: Methods and devices implementing a combination of multi-dimensional pulse position modulation (PPM) with wavelength division multiplexing (WDM) or wavelength division multiplexing multiple access (WDMA) for long range space communications are disclosed. The described multi-dimensional PPM scheme can use the laser wavelength and/or polarization as the additional dimension(s) to the time dimension. Through examples it is shown that the disclosed teachings result in a higher photon information efficiency. Various exemplary embodiments are also presented to highlight the applications benefiting from the disclosed methods and devices.

Abstract: Tracking control of a light beam is achieved at high speed and with good precision, without requiring preparation of an optical system that causes high signal loss when coupling a reception light beam with an optical fiber. A reception device for optical space communication comprises: fibers having a plurality of propagation modes with spatially different characteristics; an optical coupling system for coupling the reception light beam to the fibers; and a mode separator that separates the coupled light into a plurality of propagation modes, the adjustment axes of the optical coupling system for coupling the reception light beam to one end of the fibers being controlled on the basis of the total coupling strength to all of the modes, and the priority of control of the axes being adjusted on the basis of information about the coupling strength ratio for each mode.

Abstract: An objective of the present invention is to provide an optical communication system and an optical communication method that can reduce even a delay generated in processing of obtaining a transfer function for correcting distortion in digital coherent transmission. In the optical communication system according to the present invention, pilot data for estimating a transfer function for a transmission channel is transmitted through a transmission channel with a short transmission delay time, a transfer function of the transmission channel is estimated before receiving transmission data, and the transfer function is applied to other transmission channels.

Abstract: Systems, methods, and computer-readable media are described for performing link training to enable optical pass-through (OPT) capabilities of a network node. OPT capabilities may refer to on-chip wavelength routing for a multi-wavelength data input, whereby an intermediate node detects wavelengths that are intended for OPT and transparently passes the wavelengths through to downstream nodes. When executed at an intermediate network node, an OPT link training algorithm can result in the creation of one or more wavelength routing maps that associate wavelengths received on particular inputs to the node with particular outputs of the node. An intermediate node may generate a respective wavelength routing map for each transmit node from which it receives input data. The wavelength routing maps may together implement OPT capabilities at the intermediate node as each wavelength routing map may indicate the manner in which wavelengths are passed through the intermediate node for a given transmit node.