Abstract: Provided are a method, a system and a node for implementing APS in an OBRing network. The method comprises: a master node and a slave node separately perform optical power monitoring on respective channels, and aggregate monitoring results to the master node; when determining, according to the monitoring results, that a fault occurs, the master node sends a switching operation instruction to the slave node; and the slave node performs a switching operation and enters a protection working state. With the disclosure, a protection switching mechanism is introduced to the OBRing, which implements the processing on fault and ensures the communication quality of the OBRing.

Abstract: Consistent with an aspect of the present disclosure, optical signals are transmitted that are modulated in accordance with an 8QAM modulation format. The optical signals carry symbols of data and may be represented by a constellation in the IQ plane that includes four inner points that are symmetrically arranged about the origin, and four outer points that are uniformly distributed about the origin, but rotated relative to the inner points. The rotation is toward inner points that represent symbols for which an erroneous transition between the outer points and such inner points is more likely to result in a single bit error, instead of two bit errors, because the symbol corresponding to the outer point and the symbol corresponding to such inner point differ by just one bit. Accordingly, a binary forward error correction algorithm may be employed to correct the errored bit.

Abstract: A light detection module includes: a TO base and a TO cap; wherein the TO base is fixedly provided thereon with a first optical sensor, a support frame and a support base; the support frame is fixedly provided thereon with a beam splitter, and the beam splitter and the first optical sensor are at an angle of 45 degrees; an upper surface of the support base is fixedly provided thereon with an optical resonator and a second optical sensor, the optical resonator is located between the beam splitter and the second optical sensor, and the optical resonator, the second optical sensor and the beam splitter are on a straight line parallel to a surface of the TO base; and the TO cap is provided thereon with an opening, and the opening, the first optical sensor and the beam splitter are on a straight line perpendicular to the surface of the TO base.

Abstract: In accordance with embodiments disclosed herein, there are provided methods and systems for low-cost, long-distance, high-bandwidth laser communication system for small mobile devices and spacecraft. For example, in one embodiment, such a system includes a first station having therein: (i) a processor and a memory to implement configuration instructions for the system, (ii) a laser origination source, and (iii) a transmitter to transmit a laser signal from the laser origination source from the first station; a second station having therein: (i) a processor and a memory to implement configuration instructions for the system, (ii) a light sensor array to receive the laser signal transmitted from the first station, and (iii) a reflector to reflect back at least a portion of the transmitted laser signal back to the first station; and in which the second station is to modulate the received laser signal transmitted from the first station to encode a message onto the laser signal reflected back to the first station.

Abstract: The present invention discloses a parameter obtaining method and apparatus. In this method, multiple signals are received over a communications link on a network, where each of the received signals is corresponding to a point on a complex plane; decision is performed on each of the received signals; for each of the received signals, an error signal between the received signal and a corresponding decision signal is determined; and a complex-plane distribution feature parameter used to indicate a distribution feature, on the complex plane, of the signals received over the communications link is determined according to all the determined error signals. In this method, an inaccurate maintenance result in manual analysis of a constellation diagram is avoided.

Abstract: A self-calibration procedure for an optical transmitter is provided. During the self-calibration procedure, a phase bias of an optical modulator of the optical transmitter is set so that an in-phase path and a quadrature path of the optical modulator are in phase. Stimulus signals are supplied to the in-phase and quadrature paths of the optical modulator, over a frequency range. Detection, with a photodetector, is made of an optical output of the optical modulator at a plurality of frequency steps over the frequency range. A photodetector converts an optical output of the optical modulator to an electrical signal. First and second measurement values are generated from the electrical signal output from the photodetector. A frequency spectrum and/or time delay is computed from the first and second measurement values for each frequency step value over the frequency range.

Abstract: Techniques are described for characterizing a receiver front end of a pluggable optical module. The pluggable optical module receives an optical signal that includes a first portion having a first polarization and a second portion having a second polarization. The first portion and second portion are not coherent with one another and the power of the first portion and second portion is equal.

Abstract: An optical communication link that includes two nodes interconnected by an optical channel that comprises optical fiber(s), and that is used to communicate an optical signal comprising multiple optical signal wavelengths. The first node provides an optical signal onto the optical channel towards the second node, or receives an optical signal from the optical channel from the second node. A Raman pump provides Raman pump power into the optical fiber of the optical channel to thereby perform Raman amplification of the optical signal in the optical fiber. The second node determines a quality measurement of at least of optical wavelength signals transmitted by the first node to the second node. The second node also transmits information from the quality measurement back to the first node. A controller at the first node controls at least one parameter of the Raman pump in response to this transmitted information.

Abstract: Embodiments herein relate to a method in a network unit for monitoring a fiber line between a radio base station and a radio head in a Fiber to the Radio Head communications network. The Fiber to the Radio Head communications network comprises a ring architecture or a tree architecture of fiber, with Subcarrier Multiplexing, SCM, downstream transmissions and Wavelength Division Multiplexing, WDM, upstream transmissions. The monitoring comprises that the network unit detects an indication of a fault along the fiber line based on monitoring power. The network unit initiates, in response to detect the indication, an Optical×Domain Reflectometry, O×DR, measurement over the fiber line. Additionally, the network unit analyses a trace from the O×DR measurement for localizing the fault or for deciding that the indicated fault is not a fault along the fiber line.

Abstract: An optical switch (10) comprising: inputs (12) to receive input optical signals at respective wavelengths and having planar wavefronts; conversion apparatus (14) to convert each input optical signal into a respective optical signal having a respective helical wavefront, each helical wavefront having a different orbital angular momentum, OAM; optical multiplexing apparatus (16) to receive each helical wavefront optical signal from the conversion apparatus and to multiplex the helical wavefront optical signals into an OAM multiplexed optical signal; and optical demultiplexing apparatus (18) comprising a plurality of outputs (20), the optical demultiplexing apparatus arranged to: receive the OAM multiplexed optical signal; demultiplex the OAM multiplexed optical signal into a plurality of wavelength multiplexed optical signals each having a different OAM; reconvert each wavelength multiplexed optical signal from its helical wavefront into a respective planar wavefront; and deliver each planar wavefront wavelengt

Abstract: A system and method for channelization of a wideband radio frequency signal into multiple narrowband channels includes obtaining, a dual-banded optical signal, where the dual-banded signal is a translated wideband radio frequency signal, and where the dual-banded signal includes a signal and an idler. The method also includes modifying, by the spectral phase mask, the spectral phases of at least one of the signal or the idler, where the modifying produces a spectral phase modulated output comprising at least one of a spectrally-modulated signal or a spectrally modulated idler. The method includes outputting, by the spectral phase mask, the spectral phase modulated output to an optical phase sensitive amplifier. The method includes receiving, by the optical phase sensitive amplifier, the spectral phase modulated output, and either amplifying or de-amplifying, by the optical phase sensitive amplifier, each component of the spectrally modulated output.

Abstract: A system for determining a location of a user is provided that comprises a plurality of transmitters, each associated with a predefined physical location and each comprising a light source to provide an optical location signal; and at least one head-worn locator device with an optical receiver for receiving at least one of the optical location signals. To allow the determination of a location of a user that is wearing the head-worn locator device, each transmitter is configured to provide location information in the respectively provided optical location signal, wherein said location information corresponds to said predefined physical location of the respective transmitter.

Abstract: Provided are a method for processing an OS. The method includes: an OS sending node inserts OCh information into an overhead of an OMS of an OS; and/or, the OS sending node inserts the OCh information and optical carrier information into an OCh overhead of the OS, wherein the OCh information includes an identifier of the OCh, an NCF of an effective frequency slot of a media channel and a slot width of the effective frequency slot of the media channel, and a frequency slice granularity, and the optical carrier information includes: the number of optical carriers in the media channel, bit rates of the optical carriers in the media channel, modulation formats of the optical carriers in the media channel, NCFs of the optical carriers in the media channel, slot widths of the optical carriers in the media channel and a multiplexing method for the optical carriers.

Abstract: An optical receiver module that recovers signals from a wavelength multiplexed optical signal is disclosed. The optical receiver module includes photodiodes (PDs) arranged in an array by a pitch, an amplifier that integrates trans-impedance amplifiers (TIAs) each corresponding to the PDs, and a sub-mount that mounts the PDs thereon. The sub-mount provides metal patterns on which the PDs are mounted by the flip-chip bonding. The metal patterns compensate a difference between the pitch of the arrayed PDs and another pitch of the TIAs in the amplifier as maintaining the characteristic impedance thereof substantially equal to each other.

Abstract: Provided are a method and device for configuring an OTDR test parameter set. The above-mentioned method comprises: an FMS acquiring related information about an ODN according to a test result fed back by an OTDR; and the FMS configuring a test parameter set required for one or more subsequent OTDR tests according to the related information. According to the technical solution provided in the disclosure, the test parameter set required for initiating an OTDR test can be accurately acquired.

Abstract: Aspects of the present invention provide techniques for compensating nonlinear impairments of a signal traversing an optical communications system. A parallel array of linear convolutional filters are configured to process a selected set of samples of the signal to generate an estimate of a nonlinear interference field. The predetermined set of samples comprises a first sample and a plurality of second samples. A processor applies the estimated nonlinear interference field to the first sample to least partially compensate the nonlinear impairment.

Abstract: An apparatus includes a receiver configured to receive a signal that has traveled an optical transmission line without returning output from an optical transmitting device and synchronize with the optical transmitting device in order to demodulate the signal; a dispersion compensator configured to compensate for wavelength dispersion caused by transmission of the signal; an acquisition circuit configured to acquire a transmitting timing at which the signal has been transmitted from the optical transmitting device; a calculation circuit configured to calculate a transmission time period from the optical transmitting device to the receiver from the transmitting timing and a receiving timing at which the signal has been received with the receiver; and an amount setting circuit configured to adjust a dispersion compensation amount of the dispersion compensator in accordance with the transmission time period.

Abstract: Methods and systems for a distributed optoelectronic receiver are disclosed and may include an optoelectronic receiver having a grating coupler, a splitter, a plurality of photodiodes, and a plurality of transimpedance amplifiers (TIAs). The receiver receives a modulated optical signal utilizing the grating coupler, splits the received signal into a plurality of optical signals, generates a plurality of electrical signals from the plurality of optical signals utilizing the plurality of photodiodes, communicates the plurality of electrical signals to the plurality of TIAs, amplifies the plurality of electrical signals utilizing the plurality of TIAs, and generates an output electrical signal from coupled outputs of the plurality of TIAs. Each TIA may be configured to amplify signals in a different frequency range. One of the plurality of electrical signals may be DC coupled to a low frequency TIA of the plurality of TIAs.

Abstract: It is an object to provide a technique capable of using a single framer as a necessary framer and causing the framer to be shared among a plurality of transmission destinations and priorities when coping with a plurality of transmission destinations or priorities and a change in a bandwidth of a physical lane that is caused by a change in a modulation scheme or a change in the number of wavelengths. A multilane transmission device that allocates client signals based on a transmission destination or a priority, decides the number of virtual lanes necessary for transmission of the client signals allocated based on each transmission destination or each priority, allocates the client signals allocated based on each transmission destination or each priority to the virtual lanes whose number has been decided, and frames the client signals allocated to the virtual lanes as transport frames, multiplexes the virtual lanes into a physical lane, and transmits the framed transport frames by using the physical lane.

Abstract: Disclosed is a system and method for using visible light communication (“VLC”) to perform indoor position location. Through use of a system and method configured as set forth herein, the position of any appropriately marked person or item may be found indoors using data interconnected modules that communicate with one another via RF and visible light. A mobile receiver in the form of a tag or badge attached to the person or item to be tracked receives a VLC signal from a plurality of lighting modules, and transmits back to a processor the data it received so that the processor is able determine the tag's or badge's physical position with respect to the individual network modules.