Abstract: Apparatus and method for monitoring IP multicast delivery. One embodiment comprises an Optical Line Termination (OLT) device that includes a Network Termination (NT) device that connects to a core network, and a plurality of Line Termination (LT) devices that connect to an optical distribution network. The NT device generates an IP multicast monitoring stream directed to a group address, and transmits the monitoring stream to the LT devices. The LT devices then monitor for packets directed to the group address. When an LT device detects a loss of one or more packets directed to the group address, the LT device reports packet loss for the IP multicast monitoring stream to the NT device.

Abstract: A modular fiber optic interferometry control system and method for extracting information from superimposed waves is disclosed. The system comprises a first module for converting a radio frequency input to a multiplexed binary data stream, a second module for correlating a pseudo random number (PRN) reference with a received PRN code modulated backscattered signal, and a third module comprising control logic. In some embodiments the system further comprises one or more of a fourth module for generating a power stream, a fifth module for event interrogation, and a sixth module for noise reduction.

Abstract: A method (1200) of transmitting digital information via a nonlinear optical channel (722), comprises receiving (1202) data (702) comprising at least a portion of the digital information. A plurality of frequency domain symbols is generated (1204) from the data, and each symbol is assigned to one of a predetermined plural number of frequency sub-bands. Each sub-band may be processed separately (1206) to reduce a peak-to-average power ratio (PAPR) of a transmitted optical signal. The optical signal (12) is then generated (1208) comprising the plural number of sub-bands, and transmitted via the nonlinear optical channel (722). The plural number of frequency sub-bands is predetermined so as to reduce nonlinear optical distortion of the optical signal within the nonlinear optical channel relative to a corresponding single frequency band signal. A corresponding information-receiving method, a transmitter apparatus and a receiver apparatus are also disclosed.

Abstract: An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.

Abstract: A network capable of being used in a datacenter is described. In some embodiments, the network can comprise a set of optical fiber rings, wherein each optical fiber ring carries data traffic on one or more wavelengths, and wherein each optical fiber ring is partitioned into multiple sectors. A reconfigurable optical add-drop multiplexer (ROADM) can be coupled to at least one optical fiber in each of at least two sectors. An electro-optical-switch can be coupled to each ROADM in each of the at least two sectors. A set of switches can be coupled to each electro-optical-switch in each of the at least two sectors. The set of switches can comprise a first layer of aggregation switches that is coupled to a second layer of edge switches, wherein the edge switches can be coupled to servers in a datacenter.

Abstract: A smart receiver and smart transmitter for CATV networks where distortion is minimized using a spectrum analyzer.

Abstract: In a digital coherent communication scheme utilizing polarization-multiplexed optical signals, it may be impossible to separate transmission light and reception light from each other with high precision for transmission/reception an optical signal. An optical space transmission system according to the present invention is provided with a first transmission/reception device which radiates first reception light and second reception light whose polarization states are orthogonal to each other, and a second transmission/reception device which radiates third reception light alternately including a first reception light component whose polarization state is the same as the first reception light and a second reception light component whose polarization state is the same as the second reception light in a time-wise manner.

Abstract: A method of validating connections in an optical add/drop multiplexer (OADM) that includes a plurality of modules configured to route optical signals through the OADM, and at least one multi-fiber cable connecting modules of the OADM. A light source coupled to a first port of a first module is controlled to emit a test light. A determination is made whether or not the test light is received at a first photo-detector connected to a second port. Continuity of a connection between the first port and the second port is validated when the test light is received at the first photo-detector.

Abstract: An optical receiver may include a digital signal processor to receive an input sample that includes transmitted data, transmitted by an optical transmitter, and nonlinear distortion. The digital signal processor may process the input sample to generate an estimated data value. The estimated data value may be an estimate of the transmitted data. The digital signal processor may remove the estimated data value from the input sample to generate a noise sample. The digital signal processor may determine a nonlinear distortion value based on the input sample, the estimated data value, and the noise sample. The nonlinear distortion value may be an estimate of the nonlinear distortion included in the input sample. The digital signal processor may remove the nonlinear distortion value from the input sample to generate an output sample, and may output the output sample.

Abstract: There is provided a method of determining at least one linear-crosstalk-related parameter of an optical signal-under-test having, within an optical channel bandwidth, at least a data-carrying signal contribution and a wavelength-dependent linear-crosstalk contribution arising from a data-carrying signal contribution of an adjacent optical signal associated with an adjacent channel to the optical signal-under-test, the method comprising: acquiring at least one optical spectrum trace encompassing a quasi-continuum of closely-spaced wavelengths over a spectral range extending to at least part of both the signal under test and the adjacent optical signal; and estimating said linear-crosstalk contribution using at least spectral properties of said at least one optical spectrum trace; wherein one of said at least one linear-crosstalk-related parameter is the linear-crosstalk contribution and is determined from said estimating.

Abstract: The invention relates to an optical communication network (1) comprising a plurality of nodes (2) connected to each other by means of optical fibers (3) in a ring structure, wherein optical signals are transported at working wavelengths (?w) in a first direction in said ring structure and wherein optical signals are transported at protection wavelengths (?p) in a second direction that is opposite to the first direction in said ring structure, wherein for each node (2) at least one wavelength assignment table (WAT) is provided, wherein to each working wavelength (?w) a corresponding protection wavelength (?p) is assigned, wherein in case of a detected connection failure in said ring structure each node (2) which loses at least one connection performs for all working wavelengths (?w) affected by said connection failure a lookup in its wavelength assignment table (WAT) to determine the respective protection wavelength (?p) and tunes lasers of transceiver units to the determined protection wavelengths (?p).

Abstract: A system and method in a wavelength division multiplexing passive optical network is provided. A multiplexed optical downstream signal is transmitted from an optical line terminal to a passive distribution node. The signal is demultiplexed into a plurality of optical sub-signals. A sub-signal is transferred to an optical network termination. The received at least one sub-signal is identified. An optical wavelength of an upstream optical signal is set as a function of a predefined relationship between an optical wavelength of the received at least one sub-signal and the optical wavelength of the upstream signal. The upstream signal is transmitted to the optical line terminal via the passive distribution node.

Abstract: Embodiments of the present disclosure provide an estimation apparatus and method for nonlinear distortion and a receiver. The estimation method for nonlinear distortion includes: sampling a band-limited analog signal to obtain a sampling sequence; calculating a nonlinear perturbation coefficient in nonlinear distortion estimation based on a Nyquist pulse; calculating a nonlinear perturbation term superimposed on a signal by using the nonlinear perturbation coefficient and the sampling sequence; and calculating a nonlinear distortion waveform by using the nonlinear perturbation term. With the embodiments of the present disclosure, not only any modulation formats are compatible, but also advantages of high precision and good adaptability may be achieved.

Abstract: Methods, systems, and apparatus, for an external cavity FP laser. In one aspect, an apparatus is provided that includes a FP laser diode; a Faraday rotator (FR) coupled to receive an optical output of the FP laser diode and that rotates a polarization of the optical output; an optical fiber coupled at a first end to receive the output of the FR; a WDM filter coupled to a second end of the optical fiber to receive the optical signal from the optical fiber; and a FRM coupled directly or indirectly to an output of the WDM filter, wherein an optical output of the WDM filter is partially reflected by the FRM such that the polarization of a reflected beam is rotated, and wherein the reflected optical signal then passes through the FR with its polarization being rotated by the FR before it is injected back into the FP laser diode.

Abstract: An apparatus comprising a digital signal processor (DSP) unit configured to perform fiber dispersion pre-compensation on a digital signal sequence based on a dispersion value to produce a pre-compensated signal, wherein the dispersion value is associated with a remote optical receiver, a plurality of digital-to-analog converters (DACs) coupled to the DSP unit and configured to convert the pre-compensated signal into analog electrical signals, and a frontend coupled to the DACs and configured to convert the analog electrical signals into a first optical signal, adding a constant optical electric (E)-field to the first optical signal to produce a second optical signal, and transmit the second optical signal to the remote optical receiver.

Abstract: The present invention relates to a wavelength division multiplexing optical receiver and eliminates excess loss of one polarization component while eliminating the need for a polarization-independent operation of a light receiver. An input waveguide, made of a silicon wire waveguide, is connected to a loop waveguide equipped with a polarization rotator over a polarization beam splitter. A ring waveguide equipped with an output waveguide configuring an add-drop ring resonator array is optically connected to the loop waveguide. The output light from ports at both sides of the output waveguide is incident onto first and second light-receiving surfaces of a light receiver such that the optical distances are equal to each other.

Abstract: One embodiment provides an apparatus for coupling between a trunk passive optical network (PON) and a leaf PON. The apparatus includes a trunk-side optical transceiver coupled to the trunk PON, a leaf-side optical transceiver coupled to the leaf PON, and an integrated circuit chip that includes an optical network unit (ONU) media access control (MAC) module, an optical line terminal (OLT) MAC module, and an on-chip memory.

Abstract: An optical transceiver comprises a transmitter configured to transmit a first signal, and a receiver coupled to the transmitter and configured to receive a first compensation, wherein the first compensation is based on a pattern-dependent analysis of the first signal, and provide the first compensation to the transmitter, wherein the transmitter is further configured to compensate a second signal based on the first compensation to form a first compensated signal, and transmit the first compensated signal. An optical transmitter comprises a digital signal processor (DSP) comprising a compensator, a digital-to-analog converter (DAC) coupled to the DSP, a radio frequency amplifier (RFA) coupled to the DAC, and an electrical-to-optical converter (EOC) coupled to the RFA. An optical receiver comprises an optical-to-electrical converter (OEC), an analog-to-digital converter (ADC) coupled to the OEC, and a digital signal processor (DSP) coupled to the ADC and comprising a calibrator.

Abstract: Provided are an optical transmission system in which one can easily set a video signal cable, and an adapter that can be used in this system. There is provided an adapter for use in an optical transmission system in which an analog video signal or a digital video signal is transmitted between a pair of adapters using light. The adapter includes a first signal determination unit configured to make a determination as to whether a first electrical signal inputted to a common input terminal is an analog video signal or a digital video signal.

Abstract: A communications system made up of a number of multi-channel optical node (MCON) platforms uses free space optical communications terminals that have the ability to track, detect, measure, and respond to the acceleration or movement of the platform. Instead of using mirrors or traditional beam steering techniques, the platform uses a series of telecentric lens systems to re-align the focal plane such that beams are maintained in original pointing directions. A network of control systems is used to detect and measure movement of the platform, to re-align the platform after such movement, and to maintain connection with a number of other MCON platforms.