Abstract: A method and system for high-precision two-way fiber-optic time transfer comprising pre-adjusting, including calculating a local timing signal adjustment amount for a first fiber-optic time synchronization unit and a second fiber-optic time synchronization unit, and the corresponding adjusting. and following steps including the two fiber-optic time synchronization units conducting two-way time transfer based on a time division multiplexing transmission over an optical fiber link. The present invention realizes high-precision fiber-optic time transfer by combining two-way time transfer and bidirectional time division multiplexing technique.

Abstract: A multi-wavelength passive optical network (MW-PON) includes an optical distribution network (ODN), a plurality of optical line terminations (OLTs) and an optical network unit (ONU). The ODN includes a trunk fiber, one or more branching elements, and a plurality of distribution fibers. Each OLT is associated with an individual bi-directional wavelength channel using a corresponding single downstream wavelength and a corresponding single upstream wavelength, and supporting a specific downstream line rate and one or more distinct upstream line rates. The ONU is communicatively coupled to a respective distribution fiber, being tunable over a specific range of downstream wavelengths and a specific range of upstream wavelengths, and supporting a specific downstream line rate and a specific upstream line rate.

Abstract: A method and a device are provided for processing data in an optical network. The method includes the steps of events of a login scan are recorded by a first optical network element; the events are conveyed to a second optical network element; and the events are processed by the second optical network element. A communication system is described that includes the device.

Abstract: An advanced communications system comprising an emitter and an improved receiver (detector) utilizing modulated beams of neutrino and antineutrino waves as information carriers between the emitter and the receiver. Generation of modulated neutrino and antineutrino beams in the emitter is achieved by a laser-like medium, while detection and demodulation of the neutrino and antineutrino beams is accomplished by a second laser-like medium which registers the flux (or fluence) of modulated neutrinos and antineutrinos passing there-through by means of resonant stimulated deexcitation of lasable excited states. In addition to the information transmission utilization, the neutrino emitter and receiver (detector) system may also be employed to gather information by the probing of internal earth structures.

Abstract: An LED light and communication system in communication with a broadband over power line communications system. The LED light and communication system includes at least one optical transceiver. The optical transceiver includes a light support having a plurality of light emitting diodes and at least one photodetector attached thereto, and a processor. The processor is in communication with the light emitting diodes and the at least one photodetector. The processor is constructed and arranged to generate a communication signal. The at least one optical transceiver is engaged to a clock, and the clock is in communication with the broadband over power line communications system.

Abstract: Aspects of a method and system for feedback during optical communications are provided. In one embodiment, a system for optical communications comprises a digital-to-analog converter (DAC), a driver, and a transmit optical subsystem. The DAC is operable to receive a digital code of a plurality of digital codes and output an analog current signal having an analog current level of a plurality of analog current levels. The driver is operable to condition the analog current signal output from the digital-to-analog converter. The transmit optical subsystem is operable to generate an optical signal from the conditioned analog current signal. A digital modification of an input digital signal is dynamically controlled by a feedback path according to one or more characteristics of the optical signal. The one or more characteristics comprise a nonlinearity that may be temperature dependent.

Abstract: An optical receiver includes a processor. The processor calculates first through fourth optical intensities that respectively indicate input optical intensities of in-phase component in the first polarization, quadrature component in the first polarization, in-phase component in the second polarization and quadrature component in the second polarization. The processor calculates polarization dependent intensity ratio and phase dependent intensity ratio based on the first through fourth optical intensities. The processor calculates an input optical intensity of a polarization multiplexed optical signal based on an optical intensity of one of the first through fourth amplifiers, the polarization dependent intensity ratio, and the phase dependent intensity ratio.

Abstract: A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.

Abstract: An exemplary apparatus is provided for an optical node of an optical ring network. The optical node comprises a main branch with a wavelength blocker configured to block at least one wavelength of signals targeted to a particular node and to permit the signals received on the other wavelength channels pass, a reception unit tuned to the at least one wavelength dedicated to signals targeted to the particular node, a first optical coupler configured to transmit the signals received from a previous node of the optical ring network both to the main branch and to the reception unit, a transmission unit configured to transmit signals to a wavelength channel according to their targeted node, and a second optical coupler configured to receive the signals received from the main branch and from the transmission unit and to transmit the received signals toward a next node of the optical ring network.

Abstract: An optical communications system includes a modulator/demodulator (modem) to transmit outgoing communications data and to receive incoming communications data in a transceiver. A main detector is coupled to the modem to convert an optical signal representing the incoming communications data to an electrical signal for the modem. An adaptive data rate processor monitors the electrical signal from the main detector to determine a current power level for the optical signal. The adaptive data rate processor dynamically adjusts a data rate of the modem based on the determined current power level of the optical signal.

Abstract: A device is provided that mitigates the effects of an optical network unit (ONU) that is in a rogue state. A main processor is arranged as part of a monolithic semiconductor chip, the main processor configured to process signals from an optical telecommunication connection. A laser driver controls a laser coupled to the laser driver. Hardware logic is arranged as part of the monolithic semiconductor chip and arranged physically separate from the main processor. The hardware logic independently effects the laser driver to turn the laser off or reduce power output of the laser significantly to mitigate the effects of the ONU in the rogue state.

Abstract: A system includes an optical Y-junction coupler to receive a first modulated optical signal on a wide input path of the optical Y-junction coupler and to receive a second modulated optical signal on a narrow input path of the optical Y-junction coupler, wherein the optical Y-junction coupler generates a combined optical signal from signals received on the wide input path and the narrow input path. A multimode waveguide receives the combined optical signal from the optical Y-junction coupler and propagates a spatially multiplexed optical output signal along a transmission path.

Abstract: An optoelectronic device may include a package having a component for sending/receiving optical signals along a first direction, and a chip of semiconductor material housed within the package. The chip may have a main surface and a portion exposed on the main surface for sending/receiving the optical signals along a second direction different from the first direction. The optoelectronic device may further include a component for deflecting the optical signals between the first direction and the second direction, the component being mounted on the main surface.

Abstract: Methods of decoding N superimposed coherent optical transmission modes transmitted along a multimode optical fiber are provided where the optical signal detector comprises coherent detection hardware and a digital signal processor. The optical signals are split into N optical detection channels of the coherent detection hardware, which is used to measure the phase and amplitude of the output optical signals as a vector field matrix [ê]1×n. The digital signal processor determines the output principal states [PSout]1×n of the output optical signals from the principal state eigenvectors of an output matrix corresponding to the N propagating optical signals at the receiving portion of the data transmission link and extracts the input optical signals [M]In from the output optical signals using the output principal states [PSout]1×n, the vector field matrix [ê]1×n of the output optical signals, and a time delay ? of each output signal.

Abstract: An optical transmitter transmits to an optical receiver a multi-carrier modulated signal light by driving a light source with a modulated signal modulated with a multi-carrier modulation scheme. The optical receiver monitors reception characteristic of any of subcarrier signals included in the modulated signal and transmits a monitor result to the optical transmitter. The optical transmitter controls drive conditions of the light source based on the monitor result received from the optical receiver.

Abstract: A communication apparatus including: an optical transmission device including transceivers to transmit and receive optical signals at carrier wave frequencies different from one another; a multiplexing unit to subject the optical signals input from the transceivers to frequency multiplexing; an auxiliary transceiver to perform mixing interference of a frequency multiplexing signal and a local emission light signal having the same frequency setting as a carrier wave frequency used in a control target transceiver, to generate and output a control signal for correcting the carrier wave frequency of the control target transceiver, the auxiliary transceiver being a spare transceiver for the plurality of transceivers; and a control unit to perform control to output, to the control target transceiver, the control signal input from the auxiliary transceiver.

Abstract: An optical signal output apparatus includes: a switch having a first state or a second state in accordance with user's operation; and an optical signal output section that outputs a low-level optical signal when the switch is in the first state, whereas outputting a high-level optical signal when the switch is in the second state.

Abstract: An optical transmitter may generate a first optical signal having a first wavelength and a second optical signal having a second wavelength. The optical transmitter may output the first and second optical signals to a link without performing a multiplexing operation. The optical transmitter may output part of the first optical signal to the link while part of the second optical signal is being output to the link. An optical receiver may receive the first and second optical signals, via the link, as separate optical signals. The optical receiver may receive part of the first optical signal from the link while part of the second optical signal is being received from the link. The optical receiver may provide the first and second optical signals to a photodetector array that includes a first photodetector to detect the first optical signal and a second photodetector to detect the second optical signal.

Abstract: An optical receiver circuit includes: a substrate; and an optical waveguide device that is formed on the substrate. The optical waveguide device includes: a first optical splitter section branching the signal light into a first signal light propagation waveguide and a second signal light propagation waveguide and; a second optical splitter section branching the local-oscillator light into a first local-oscillator light propagation waveguide and a second local-oscillator light propagation waveguide; a first optical coupler section that combines the signal light propagating through the first signal light propagation waveguide and the local-oscillator light propagating through the first local-oscillator light propagation waveguide with each other; a second optical coupler section that combines the signal light propagating through the second signal light propagation waveguide and the local-oscillator light propagating through the second local-oscillator light propagation waveguide with each other.

Abstract: A method and apparatus for communications in a passive optical network (PON) system are provided. An optical line terminal (OLT) generates a PON downstream Physical Layer (PHY) frame comprising a downstream physical synchronization block (PSBd) that comprises a wavelength identification (ID) of at least one downstream wavelength of the plurality of downstream wavelengths. The OLT sends the PON PHY frame comprising the wavelength ID in the PSBd to ONU for confirming the at least one downstream wavelength.