Abstract: The present invention discloses a method and a system for implementing alternative routes in optical transmission network of WSON. By using the method and the system the following alternative routes implementing process is realized: computing the alternative routes of each subsegment independently based on a constraining condition distributed by a managing plane, and combining the computed alternative routes of each subsegment to form complete alternative routes. The present method and system for implementing alternative routes is capable of obtaining more alternative routes than those of prior art, and takes full advantage of network resource topology.

Abstract: In general, the 1G-EPON standard specifies its upstream waveband broadly to allow for low cost lasers to be used to transmit upstream. Often, however, the lasers actually used by many 1G-ONUs to transmit upstream only occupy a narrow waveband that does not overlap with the upstream waveband specified by the 10G-EPON standard. The present disclosure is directed to systems and methods that exploit this fact to efficiently provide for the coexistence of 10G-EPON and 1G-EPON over the same set of optical fibers in the upstream direction.

Abstract: An optical passive repeater is provided. The repeater is operated under a state of polariton Bose-Einstein condensation (BEC). A phase transition from a thermal polariton state to a condensed polariton state is controlled, where system temperatures and densities are lower than thermal dissociation temperatures and nonlinear saturation densities, respectively. Original input multimode laser signals are transformed into final output single-mode laser signals. Thus, the polariton BEC passive repeater becomes a power-efficient and low-cost device to increase the reach of optical links without sacrificing its signal quality and integrity.

Abstract: An electro-optical single-sideband modulator comprising: an electro-optical substrate; a bimodal optical waveguide structure formed in the substrate to support different optical modes having associated optical frequencies and optical propagation constants and comprising an optical input to receive an input optical carrier signal having an optical frequency, and a pair of optical outputs to output corresponding SSB modulated optical signals, each having an optical frequency spectrum with a single side lobe; and an electrode structure formed on the substrate to receive an input electrical modulating signal having an associated electrical frequency and electrical propagation constant, and to responsively apply an electrical field to the bimodal optical waveguide structure.

Abstract: A method, an optical node, and an optical network include a power controller configured to bring channels in-service in parallel over multiple cascaded optical nodes quickly, efficiently, and in a non-service affecting manner. The method, node, and network utilize multiple states of a control loop that maintains a stable response in downstream optical nodes as channels are added in parallel. Further, the power controller is configured to operate independently alleviating dependencies on other power controllers and removing the need for coordination between power controllers. The method, node, and network provide efficient turn up of dense wave division multiplexing (DWDM) services which is critical to optical layer functionality including optical layer restoration.

Abstract: An optical communication apparatus includes a variable resistor unit, a measurement unit, and a control unit. The variable resistor unit is arranged at a pre-stage of an electrical/optical conversion unit, which converts an electrical signal obtained by converting an input packet to an optical signal having a waveform corresponding to a potential difference between a positive phase component and a negative phase component of the electrical signal by using the potential difference. The variable resistor unit provides a resistor that varies a midpoint of potential of the positive phase component or the negative phase component. The measurement unit measures a ratio of a presence period, which is a period where the input packet is present, to a sum of the presence period and a non-presence period. The control unit controls a value of the resistor provided to the positive phase component or the negative phase component based on the ratio.

Abstract: A transmitter in a visible light communication system is provided, in which a plurality of light sources emit light in different colors, a data converter converts data to predetermined chromaticity coordinates, a data transmitter emits light having a chromaticity corresponding to the chromaticity coordinates by controlling light intensity of each of the light sources, and a pre-light emitter emits light having chromaticities corresponding to all chromaticity coordinates by controlling the light intensity of each of the light sources, before the light intensity control of the data transmitter.

Abstract: A photonic waveform generator and a method of generating an electrical waveform based on a photonic signal are disclosed. The generator includes an input port for receiving an optical signal, a pulse shaper coupled to the input port and configured to Fourier transform the optical signal and apply a pre-distort waveform onto optical spectrum of the optical signal, a dispersive pulse stretcher coupled to the pulse shaper, an optical-to-electrical converter coupled to the dispersive pulse stretcher, and an output port coupled to the optical-to-electrical converter, the pre-distortion removes distortion of the electrical signal that exists in the absence of the pre-distortion caused by violation of far field limitation between the optical signal and the electrical signal.

Abstract: A modulator with polarization marking comprising two input ports for receiving two optical signals at one wavelength, and exhibiting essentially perpendicular optical polarization states, capable of phase-modulating those signals with data signals and of combining them with polarization, characterized in that it comprises a source of phase overmodulation for overmodulating the phase of one of said two optical signals, said phase overmodulation exhibiting a modulation frequency substantially lower than the modulation frequency of said data signals. A method and a coherent receiver are also disclosed.

Abstract: In an analog, fiber-based signal distribution system, a periodic electrical signal is frequency-multiplied by a factor of N, is converted to an optical signal, is optically amplified, is split among one or more optical fibers, is delivered by fiber to one or more remote units, is converted back to an electrical signal, is frequency-divided by the factor of N back to its original frequency, and can be used to generate synchronized clock signals at the remote units. The optical amplifier imparts a phase noise that is relatively independent of frequency, so that the phase noise contribution from the optical amplifier is advantageously decreased when the frequency divider reduces the frequency of the electrical signal. Compared to a distribution system that does not increase, then decrease, the frequency by a factor of N, the phase noise contribution from the optical amplifier is reduced by 20 log 10(N).

Abstract: Optical devices in optical network exchange signals at a plurality of wavelengths via a plurality of pathways. Each of the optical devices is associated with a corresponding wavelength and includes multiple optical inputs/outputs (I/Os) to exchange signals at the corresponding wavelength via the plurality of pathways. During maintenance or failure of one of the optical I/Os in an optical device associated with a wavelength, communications are maintained in the optical network by switching communications at a same wavelength to another a different pathway and/or reforming the optical network using other wavelengths. For example, an optical network unit (ONU) may identify an error in a first wavelength associated with a first optical device included in an optical line terminal (OLT) and may forward data using a second wavelength associated with the other optical device included in the OLT.

Abstract: A method and apparatus for switching an optical data stream via an optical network node, capable of switching optical data received at input ports to output ports. The method includes the following steps performed by a processing chain upon detection of a stream at a given wavelength by a given input port: determining a resource of the node based on a predetermined routing policy such that, for a given wavelength common to source and destination nodes of the stream, routing within the network is carried out according to a routing tree covering the network, a root of the tree being the destination node; consulting an occupancy table for the resource, indicating if at least one possible preceding stream is using the resource; determining a delay to be applied by the processing chain to prevent a collision between the stream and the possible preceding stream; and configuring the processing chain to apply the delay.

Abstract: A method of transmitting a data signal using an optical transmitter of an optical communications system. The optical transmitter is configured to modulate an optical carrier in successive signalling intervals to generate an optical signal. A modulation scheme is provided which comprises a multi-dimensional symbol constellation. The modulation scheme is designed such that an average degree of polarization of a modulated optical signal output from the optical transmitter has a first value when averaged across a first signaling interval, and has a second value when averaged across more than one and fewer than 100 signaling intervals. The second value is less than 10 percent of the first value. During run-time, an encoder of the optical transmitter encoding a data signal to be transmitted as symbols of the constellation, and a modulator of the optical transmitter modulating available dimensions of the optical carrier in accordance with the symbols.

Abstract: The present invention provides a nonlinear compensating apparatus and method and a transmitter. The nonlinear compensating apparatus includes: an information sequence acquiring unit, configured to acquire a symbol information sequence of the pulse signal; a perturbation quantity acquiring unit, configured to calculate, by pre-obtained weighting coefficients to which each item corresponds, the weighted sum of interaction items of pulses on one or more moments relative to the current moment; a perturbation quantity processing unit, configured to combine the items of the perturbation quantity based on the weighting coefficients; and an information compensating unit, configured to calculate a difference between the symbol information sequence and the processed perturbation quantity to obtain a compensated symbol information sequence. With the embodiments of the present invention, the complexity of calculation may be further lowered, and requirements on hardware may also be lowered.

Abstract: A system for performing in-band reflection analysis in a passive optical network. The system comprises an optical line terminal (OLT) that includes a transceiver for transmitting continuous downstream data modulated on a first wavelength and receiving upstream burst data modulated on a second wavelength, the OLT further includes a receiver for receiving signals reflected from the PON that are modulated on the first wavelength, wherein the continuous downstream data comprises user data and a test data pattern; and a reflection analysis unit for cross-correlating between a time-shifted version of the transmitted test data pattern and the reflected signals, wherein the test data pattern is time-shifted relatively for an optical location to be tested.

Abstract: Systems and methods for Ethernet Passive Optical Network Over Coaxial (EPOC) power saving modes are provided. The EPOC power savings modes allow an EPOC coaxial network unit (CNU) to enter a sleep mode based on user traffic characteristics. The sleep mode may include powering down one or more module of the EPOC CNU, including radio frequency (RF) transmit/receive circuitry and associated circuitry. In embodiments, the EPOC CNU may enter sleep mode based on instructions from an optical line terminal (OLT) or based on its own determination. Embodiments further include systems and methods that allow the EPOC CNU to maintain synchronization with a servicing coaxial media converter (CMC) when it enters a sleep mode.

Abstract: An optical frequency-division multiplexer includes: a first optical coupler configured to receive a first wavelength-division multiplexed light obtained by wavelength-division multiplexing a first carrier light and a first monitor light and split the first carrier light and the first monitor light from each other; an optical modulator configured to optically modulate the split first carrier light using a signal including a first data signal so as to multiplex the first data signal with the first carrier light; a receiver configured to receive a branched part of the split first monitor light and demodulate a second data signal from the first monitor light; and a second optical coupler configured to couple a remaining part of the split first monitor light and the first carrier light with which the first data signal has been multiplexed.

Abstract: An optical reception device (10) includes an electrical signal converter (110) that converts an optical signal serving as an input polarization multiplexed signal into electrical signals of respective polarization components, a signal processor (120) that executes digital signal processing for digital signals generated by executing A/D conversion processing, and a phase difference output unit (130) that detects a phase difference generated between the polarization components of the optical signal based on the signals having undergone digital signal processing, and outputs information representing the phase difference. The signal processor (120) compensates for the distortion of the optical signal based on the information representing the phase difference.

Abstract: The disclosure provides a method and system for realizing power saving mechanism management between an Optical Network Unit (ONU) and an Optical Line Terminal (OLT). The method includes: passing power saving information between the ONU and the OLT through an extended Operation Administration and Maintenance (OAM) frame; closing/opening an optical module of the ONU based on the obtained power saving information. With the method of the disclosure, the optical module is closed in time when the optical module of the ONU is not needed, thus reducing power consumption of the ONU, and enabling interaction between the ONU and the OLT to meet the requirement for power saving and emission reduction.

Abstract: An optical communication system provides coherent optical transmission for metro applications. Relative to conventional solutions, the optical communication system can be implemented with reduced cost and can operate with reduced power consumption, while maintaining high data rate performance (e.g., 100 G). Furthermore, a programmable transceiver enables compatibility with a range of different types of optical networks having varying performance and power tradeoffs. In one embodiment, the optical communication system uses 100 Gb/s dual-polarization 16-point quadrature amplitude modulation (DP-16QAM) with non-linear pre-compensation of Indium Phosphide (InP) optics for low power consumption.