Abstract: Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM.

Abstract: A transponder among a plurality of transponders that are connected with a client device via a plurality of optical couplers, the transponder includes a protection timer configured to be activated when an alarm indication signal transmitted from the client device is received, and a controller configured to control transmission of an optical signal to one of the plurality of optical couplers when the protection timer times out, wherein a timeout value of the protection timer is set to a value different from a timeout value of a protection timer included in another transponder.

Abstract: Multi-domain scheduling for subordinate networking is contemplated. The scheduling may include controlling a terminal to facilitate interfacing an Internet Protocol (IP) network with a point-to-multipoint (P2MP) network where the P2MP network includes one or more aggregating devices to facilitate interfacing signaling with devices/units associated with one or more subordinate P2MP networks.

Abstract: A cable adapter apparatus (201) is disclosed having at least one adapter (203) and a controller (206). The adapter apparatus is operable to: determine connection of a cable test device (208) to a first port (230, 231, 232) of the at least one adapter; receive data from the test device relating to at least one tested characteristic of a cable (251, 261, 271) connected to a second port (240, 241, 242) of the at least one adapter opposite said first port; and store the received tested cable characteristic data in a memory. The stored tested cable characteristic data may be made available to a cable monitor application (225). A method including storing data resulting from processing data from a reflected signal is also disclosed. A modified reflectometer device adapted to be connected to a first port of a cable adapter is also disclosed.

Abstract: This disclosure describes the Fast Chromatic Dispersion Estimation (FCDE) techniques which corrects for chromatic dispersion in high data rate optical communications systems such as some coherent optical communications systems. FCDE may utilize transform such as fast-Fourier transforms to estimate the chromatic dispersion. From an estimate of the chromatic dispersion, the techniques may determine filter tap coefficients for compensating the chromatic dispersion.

Abstract: An optical transmitter implemented with two QPSK (Quadrature Phase Shift Keying) modulators is disclosed. Each of the QPSK modulators provides a waveguide made of semiconductor material inducing the QCSE (Quantum Confined Stark Effect) by a bias supplied thereto. The optical performance of one of the QPSK modulators is determined by supplying a deep bias to the other of the QPSK modulator to eliminate the optical output therefrom.

Abstract: An optical network (10) comprising an optical network element (12) comprising a first optical transmitter (14), a first controller (16), an optical receiver (18), a second optical transmitter (22), a second controller (24) and optical receiver apparatus (26). Said first controller is arranged to control said first optical transmitter to generate and transmit a first optical signal in response no second optical signal being detected. Said first controller is arranged to iteratively generate and transmit said first optical signal at different wavelengths of a plurality of wavelengths until said second optical signal is detected, and is further arranged to subsequently maintain generation and transmission of said first optical signal at said wavelength at which said second optical signal is detected. Said second controller is arranged to control said second optical transmitter to generate and transmit said second optical signal following detection of said first optical signal by said optical receiver apparatus.

Abstract: The present invention refers to a method for operating a coherent optical packet receiver comprising at least one linear physical impairment compensation filter wherein the settings of at least one linear physical impairment compensation filter applied on a received optical packet having at least one given travelling parameter are determined in function of previous settings determination of said at least one linear physical impairment compensation filter achieved on at least one optical packet having a similar at least one travelling parameter as said received optical packet.

Abstract: The present disclosure includes systems and techniques relating to reconfigurable optical transmitters. In some implementations, an apparatus, systems, or methods can include multiple ports to receive independent optical data signals or independent electrical signals that are converted into independent optical data signals, at least one optical pump laser, and one or more nonlinear optics elements configured and arranged to generate a phase conjugate for each of the independent optical data signals at least by combining the respective independent optical data signal with an output of the optical pump, and generate an output optical signal from the independent optical data signals at least by combining each of the independent optical data signals with its corresponding generated phase conjugate.

Abstract: A hybrid communications system implements different communication technologies to communicate data and information for particular communications directions in different portions of the system. Power line communications (PLC) signaling is used to deliver data and information from a gateway device to a light access point. Visible light communications (VLC) signaling is used to communicate data and information from the light access point to a user equipment (UE) device. Wireless radio signaling, wireless infrared (IR) signaling, or a combination of wireless IR signaling and PLC signaling is used to communicate data/information from the UE device to the gateway device. To efficiently control the VLC communications channel between the light access point and UE device, the UE device measures the VLC channel, e.g., calculating SNRs on a per VLC tone basis, and communicating VLC channel quality feedback information to the gateway device, which is forwarded to the light access point.

Abstract: A highly reliable optical switching device and optical switching method ensure restoration of the failure in the large-capacity high density wiring of the multicore fiber with the general number of cores (7 cores, 19 cores and the like). An optical transmission system which transmits a supervisory control signal concerning a transmission path switching to one or more cores of a single or multiple multicore fibers, an active signal to one or more cores, and a standby signal to one or more cores includes optical switching devices connected to respective ends of the optical transmission system. Upon detection of the transmission failure of the active signal based on the signal transmission condition and information from the supervisory control signal, it is switched to the standby signal. The supervisory control signal is transmitted to the center core of the multicore fiber.

Abstract: An optical system may include: a demultiplexer to receive an optical signal and to demultiplex the optical signal into a plurality of optical channels; a detector circuit to: receive the plurality of optical channels, and identify a predetermined channel identification trace tone frequency for an optical channel of the plurality of optical channels; and a receiver to: receive the optical channel with the identified predetermined channel identification trace tone frequency from the detector circuit, and process the optical channel.

Abstract: An optical transmission apparatus includes an optical transmitter that includes a light emitting element and a driver circuit for the light emitting element, a temperature sensor that detects a temperature of the optical transmitter, and a controller that switches an operation mode of the optical transmitter from a normal mode to a low-power mode so as to reduce a heating effect to the light emitting element and allow an operation of the light emitting element to continue when the temperature detected by the temperature sensor is equal to or higher than a given temperature.

Abstract: A continuous-mode wavelength converting apparatus, a burst-mode wavelength converting apparatus, a remote termination apparatus and a central office termination apparatus for converting a burst-mode upstream wavelength signal into a continuous-mode upstream wavelength signal, and thereby transmitting the signal to a long distance and increasing link capacity. The continuous-mode wavelength converting apparatus may convert a received burst-mode upstream electric signal into a continuous-mode upstream electric signal by inserting a first frame at the front of the signal as an indicator of a start of the signal, inserting a second frame at the end of the burst-mode upstream electric signal as an indicator of an end of the signal, and inserting an idle signal into at least one remaining region of the burst-mode upstream electric signal.

Abstract: A method and device for determining an output of a visible frame in at Visible Light Communication (VLC) device are provided. A first VLC device determines whether to permit a second VLC device to generate visible frames, and transmits, to the second VLC device, visible frame information indicating whether the second VLC device is permitted to generate the visible frames.

Abstract: An optical network includes receiving inter-rack traffics from transmitter racks, converting by transmitters the inter-rack traffics to respective wavelength division multiplexing WDM optical signals, receiving and routing by a cyclic interleaver the optical signals from the transmitters to output ports in a cyclic manner, converting respective routed optical signals from the cyclic interleaver into respective electrical signals, and demodulating OFDM formats from respective converted optical signals containing signals for respective receiver racks.

Abstract: A method and apparatus includes an optical source for a single order single-sideband suppressed-carrier optical signal with a bandwidth that scales from over 1 gigaHertz to greater than 20 gigaHertz. In an example embodiment, an apparatus includes a stable laser source configured to output an optical carrier signal at a carrier frequency. The apparatus includes a radio frequency electrical source configured to output an electrical radio frequency signal with a radio frequency bandwidth less than one octave. The apparatus also includes an optical modulator configured to output an optical signal with the optical carrier signal modulated by the radio frequency signal in a plurality of orders of optical frequency sidebands. The apparatus further includes an optical filter configured to pass one single order optical frequency sideband of the optical signal.

Abstract: An optical transmitter includes: a modulator driver to generate a drive signal from an input signal; a modulator to generate a modulated optical signal according to the drive signal; an amplitude detector to detect an input amplitude representative of an amplitude of the input signal; and a controller to generate a waveform control signal according to the input amplitude detected by the amplitude detector. The modulator driver controls a waveform of the drive signal according to the waveform control signal.

Abstract: An apparatus, e.g. an optical receiver, includes an optical front end and an equalizer. The front end is configured for receiving an optical signal bearing first and second symbols on respective first and second polarization channels. The equalizer is configured to 1) select a first cost function if the first symbol has greater energy than the second symbol, 2) select a second different cost function if the second symbol has a greater energy than the first symbol, and 3) based on the selected cost function, update coefficients of an adaptive filter configured to demultiplex and equalize the first and second polarization channels.

Abstract: The present invention provides a signal detection method, including: receiving, by a frequency mixer, wavelength division multiplexing signals and a local oscillator signal, where a wavelength of the local oscillator signal and a wavelength of a target signal in the wavelength division multiplexing signals are the same; a frequency mixer performs interference on the wavelength division multiplexing signals through the local oscillator signal to obtain a coherent signal formed by the local oscillator signal and the target signal; sending the coherent signal to a transimpedance amplifier for amplification to obtain a voltage signal; and obtaining the power of the target signal according to a power amplitude of the voltage signal.