Abstract: An apparatus and methods for generating multi-level output signals for use by an optical modulator are provided. The apparatus comprises a plurality of input signal lines each configured to receive a binary input signal, an output signal line and a plurality of amplifier stages. The amplifier stages are each connected between one of the input signal lines and the output signal line so as to each produce an output voltage on the output signal line of either a first level or a second level. The level of the output voltage is based on the binary signal at the respective input signal line, and the output voltages of the respective plurality of amplifier stages collectively produce a summed analog output voltage on the output signal line at two or more different levels each configured to drive an optical modulator.

Abstract: An optical node includes a wavelength splitter configured to split optical signals comprising multiple optical wavelengths into separate outputs, with each of the separate outputs having a different wavelength. The optical node further includes a detector configured to detect optical signals associated with packets at each of the separate outputs, and determine a modulation applied to the optical signals at each of the separate outputs. The optical node also includes a processing unit configured to identify destination optical nodes for the packets based on the determined modulation.

Abstract: A software-defined (SD) optical network is disclosed. An SD optical line terminal (OLT) includes a global SD controller, one or more SD OLT drivers connected to the global SD controller, and an underlying hardware component connected to each of said one or more SD OLT drivers. An SD optical network unit (ONU) includes a local SD controller, one or more SD optical network unit (ONU) drivers connected to the local SD controller, and an underlying hardware component connected to each of said one or more SD ONU drivers, wherein the local SD controller manages said one or more SD ONU drivers by issuing commands communicated to said one or more SD ONU drivers, and wherein each of said one or more SD ONU drivers implements a required function on the underlying hardware component. Other apparatuses, systems, and methods also are disclosed.

Abstract: A method for routing C-band and L-band optical signals, and a system, apparatus, and computer program that operate in accordance with the method. The method comprises selecting one or more C-band optical signals using one or more C-band components, resulting in one or more selected C-band optical signals. One or more L-band optical signals are selected using one or more L-band components, resulting in one or more selected L-band optical signals. The selected C-band and L-band optical signals are combined.

Abstract: An optical transmission system 1 includes an optical transmitter 10 and an optical receiver 200. The optical transmitter 10 includes, a multiplexed code sequence generation unit 90a arranged to multiplex a code included in the transmission code sequence to be time shifted, and an optical transmission unit 90b that converts a multiplexed code sequence into a light signal and transmit it. The optical receiver 200 includes, an optical reception unit 240 that receives and converts the light signal transmitted from the optical transmitter 10 into a code sequence, and a transmission code sequence regeneration unit 380 that regenerates the transmission code sequence by identifying a code based on a value of a plurality of codes each corresponding to one another included in the code sequence.

Abstract: Disclosed is a bidirectional light transmitting and receiving device which includes a first conductive plate; a second conductive plate; at least one first lead pin which penetrates the first conductive plate and includes a first conductor and a first dielectric surrounding the first conductor; at least one second lead pin which penetrates the second conductive plate and includes a second conductor and a second dielectric surrounding the second conductor; a light receiving unit which is connected with the at least one first lead pin; and a light transmitting unit which is connected with the at least one second lead pin, wherein the first conductive plate is electrically isolated from the second conductive plate.

Abstract: Techniques are provided to estimate a distance of one received optical subchannel to one or both of its neighbor (adjacent) subchannels. An optical field comprised of a plurality of subchannels of optical signals at respective wavelengths is received on an optical fiber. Using coherent optical reception in conjunction with analog-to-digital conversion, the received optical field is converted to digital complex valued data. The digital complex valued data is transformed to the frequency domain to produce spectrum data. Using either a peak method or a gap method, a distance or spacing is computed between a subchannel of interest among the plurality of subchannels and at least one neighbor subchannel based on the spectrum data.

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: There is provided a method for determining an in-band noise parameter, such as the Optical Signal-to-Noise Ratio (OSNR), on an optical signal-under-test (SUT) propagating along an optical communication link and comprising a data-carrying signal contribution of any arbitrary degree of polarization and a noise contribution. A spectral shape trace of data-carrying signal contribution in the SUT is estimated using a reference optical spectrum trace of a reference signal which comprises a data-carrying signal contribution that is spectrally representative of the data-carrying signal contribution of the SUT and a noise contribution which is at least approximately known. The data-carrying signal contribution is mathematically discriminated from said noise contribution in the SUT using the spectral shape trace and the test optical spectrum trace. The in-band noise parameter is then determined at least from the mathematically discriminated noise contribution.

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: In a PON system, an ONU includes a receive buffer that stores therein a signal in a downstream direction transmitted from an OLT and a PON control unit that controls transition to a power-saving state and transition to a normal state for the reception buffer. The OLT includes a transmission buffer that stores transmission data to be transmitted to the ONU and the PON control unit that transmits the downstream power-saving-state transition request that requests the ONU to transition to the downstream power-saving state when it is determined that transmission data addressed to the ONU is not present in the transmission buffer. The PON control unit sets the reception buffer to a power-saving state for a predetermined downstream sleep time requested based on the downstream power-saving-state transition request.

Abstract: Embodiments of the present disclosure provide a data synchronization method and system, and an optical network unit. An ONU receives synchronization data that is transmitted by a first OLT through a GEM port corresponding to a predetermined GEM port ID or a logical link corresponding to a predetermined LLID, and stores the synchronization data. When a fault occurs on the first OLT or on a backbone optical fiber connected to the first OLT, the ONU transmits the synchronization data to a second OLT so that the second OLT recovers services according to the synchronization data.

Abstract: An electro-optical switch (170) for receiving N data streams optically, each of said N data streams having an amplitude and a phase and each being located at an optical center frequency FO1+RFM, where FO1 is a first optical modulation frequency and RFM is a signal center frequency. The electro-optical switch is arranged to convert the N data streams to electrical data signals at the data stream's signal center frequency RFM, the electrical data signals having the amplitude and phase of the optical data stream. The electro-optical switch is further arranged to convert electrical data signals to optical output signals at optical center frequency FO2+RFOut with the amplitude and phase of the first electrical data signal maintained, and to transmit the optical output signals, with RFM and RFOut, being equal to or different from each other, and FO1 and FO2 also being equal to or different from each other.

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: A method and system for encoding and determining labels in a Dual Polarization (DP) Quaternary Phase Shift Keying (QPSK) signal is provided. A label frame, signature sequence, and data payload are combined using a complementary constant-weight code encoding (CCWC) encoder, the output of which is deinterleaved and differentially precoded to generate a polarized tributary of a DP-QPSK signal. This encoding can be duplicated for a second tributary of the DP-QPSK signal. The label can be determined using one or more polarizers and corresponding low-speed photodetectors, each applied to a copy of the DP-QPSK signal. The strongest output of the photodetectors is then used to determine the label. Alternatively, the DP-QPSK signal can be viewed as having XI, XQ, PH, and PV tributaries. These tributaries can then be translated into XI, XQ, YI, and YQ tributaries are encoded into a standard DP-QPSK signal.

Abstract: A method and apparatus for providing RF-photonic filtering link. Specifically, one embodiment is an apparatus comprising a radio frequency (RF)-photonic filter for filtering an RF signal, where the RF-photonic filter comprises a loop comprising an electro-optical modulator, an optical fiber, a photo detector. Another embodiment is a method of operating an RF-photonic filter comprising applying a reference signal to the RF-photonic filter; selecting a reference frequency for the RF-photonic filter upon the RF-photonic filter locking to the reference frequency, disconnecting the reference signal; and applying an RF input signal to the RF-photonic filter to lock the RF input signal to the RF-photonic filter.

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 present disclosure provides short-term optical recovery systems and methods in coherent optical receivers to minimize recovery time for fault scenarios and signal reacquisition while maintaining robust signal acquisition. The short-term optical recovery systems and methods include special techniques and algorithms to minimize recovery time. The short-term optical recovery systems and methods include an expedited acquisition engine that includes a reference clock recovery, a compensator to remove chromatic dispersion, a burst framer, and a compensator to remove polarization dispersion. Importantly, the expedited acquisition engine uses a memory-oriented architecture to allow some properties of the acquisition engine to be stored during initial acquisition and, hence, later on be deployed in any fault scenario to further expedite recovery of a signal. The expedited acquisition engine leverages on a frequency aligned Local Oscillator (LO) as well as pre-calculated dispersion maps and equalizer coefficients.

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: A signal generating method and apparatus in the field of signal technologies are provided. The method includes: adjusting an incident angle of an optical signal entering a polarization beam splitter, so that the polarization beam splitter outputs a first optical signal and a second optical signal that have a preset power ratio; performing QPSK modulation on the first and second optical signal respectively by using a first and second externally input data streams, to obtain a first and a second QPSK optical signal; before the first QPSK optical signal and the second QPSK optical signal are input into a polarization beam combiner, adjusting a polarization state of the first or the second QPSK optical signal; when the polarization states of the two QPSK optical signals are the same, outputting a 16QAM signal; and when the polarization states of the two QPSK optical signals are orthogonal, outputting a DP-QPSK signal.