Abstract: An electro-optical system for exchanging quantum information between optical qubits and including a superconductive microwave cavity; an electro-optical material; a superconductive qubit circuit formed on the electro-optical material including a superconductive qubit; a dipole antenna, formed on the electro-optical material for directly coupling the superconductive qubit to the superconductive microwave cavity; an optical input for receiving input optical photons; a microwave input for receiving input microwave photons; and an optical output for outputting modulated optical photons, wherein a frequency and a phase of the optical photon is modulated with a state of the superconducting qubit by the dipole antenna.

Abstract: A towed system for underwater electromagnetic prospecting for use with a seaward vessel is provided. The towed system comprises a first portion, a second portion, and a tow cable. The first portion is located on the vessel and includes a controller and a power supply system. The second towed portion is for submersion in the water and transmits an electromagnetic waveform and receives a corresponding electromagnetic signal. The tow cable connects the first portion with the second portion. The tow cable includes at least a pair of suitable conductors for delivering to the second portion a power signal generated by the first portion and at least one optical fiber for carrying data communications between the first portion and the second portion. The transmitted and received signals are digitized and this information is sent digitally to the controller in the first portion.

Abstract: An OLT, which is a station-side apparatus in a PON system, is connected to an ONU via an optical fiber. The OLT includes: an optical receiver which receives a burst signal from an ONU; a burst header detection unit which detects a certain delimiter pattern included in a received burst signal so as to establish synchronization of the burst signal; and a control unit which allows the burst header detection unit to perform detection of a delimiter pattern during a predicted reception period of a burst signal.

Abstract: Broadband access networks are driving the upgrade of DWDM networks from 10 Gb/s per channel to more spectrally-efficient 40 Gb/s or 100 Gb/s. Signal quality degradation due to linear and non-linear impairments are significant and error control coding and signal processing solutions play increasingly key roles in meeting increasing demand, providing improved quality of service, and reduced cost. It would be beneficial to reduce the power consumption of optical receivers for optical links exploiting for example LPDC encoding. Accordingly, the inventors have established a low complexity soft-decision front-end compatible with deployable LDPC codes in next-generation optical transmission systems. Beneficially the optical receiver design can be retro-fitted into deployed hard-decision based optical systems and replaces the 3-to-2 encoder of the prior art in the electrical portion of the receiver with a single gate design. Further, the design may act as a 2-bit Flash ADC in multimode fiber based optical receivers.

Abstract: Described herein is an optical channel monitor (100), including a plurality of input ports in the form of optical fibers (102) disposed in a vertical “port displacement” dimension. Each fiber (102) inputs a respective optical beam (103) having a plurality of individual wavelength channels. A lens (104) collimates each beam and converges the beams in the port displacement dimension to a focal plane (105). The collimated and converged beams are incident onto a rotatable micro-electromechanical system (MEMS) mirror (106), which selectively directs each optical beam onto a wavelength dispersion element in the form of a grism (108) at a predetermined angle (denoted by ?) in a horizontal “dispersion” plane. The grism (108) spatially separates, in the dispersion plane, the wavelength channels contained within each optical beam (103) by diffraction. The angle at which each channel is diffracted is controlled by the angle ?.

Abstract: An optical transmitter includes an EA modulator, a photocurrent detection circuit, a modulator drive circuit, and a CPU. The EA modulator converts an input signal into an optical signal and outputs the optical signal. The photocurrent detection circuit detects an optical absorption current (a photocurrent) in the EA modulator. The modulator drive circuit controls the EA modulator. The CPU calculates a voltage to be applied to the modulator drive circuit based on the optical absorption current detected by the photocurrent detection circuit.

Abstract: A light transmitter transmits multiple light packets, each formatted to include a predetermined phase synchronization field (PSF) and a same message comprising a series of bits. The PSF and each bit are each represented as light that is intensity modulated over a bit period at a corresponding frequency. The light packets are transmitted at different start-times to cause a receiver to sample each packet with a different phase of a fixed, asynchronous sample timeline. The PSF and message are demodulated from each of the sampled light packets. If the demodulated PSF matches the predetermined PSF, then the corresponding demodulated message is declared valid.

Abstract: A system and method for optical switching of networks in a multi-node computing system with programmable magneto-optical switches that enable optical signal routing on optical pathways. The system includes a network of optical links interconnecting nodes with switching elements that are controlled by electrical control signals. Data transmission is along the optical links and an optical pathway is determined by the electrical control signals which are launched ahead of optical signal. If links are available, an optical pathway is reserved, and the electrical signal sets the necessary optical switches for the particular optical pathway. There is thereby eliminated the need for optical-electrical-optical conversion at each node in order to route data packets through the network. If a link or optical pathway is not available the system tries to find an alternative path. If no alternative path is available, the system reserves buffering. After transmission, all reservations are released.

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: 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: A method for nonlinearity compensation for an optical transmission link includes determining a dispersion effect of a transmission link; applying a phase conjugation to the transmission link, the phase conjugation responsive to an input wave over the transmission link and providing a conjugated version of the input wave; and configuring an optimum equivalent link responsive to the phase conjugation after the transmission link to compensate for a non-linear dispersion effect from said transmission link.

Abstract: An optical hybrid (100) generates a first optical signal by causing local light to interfere with a received optical signal which is received from an outside with a first phase difference. In addition, the optical hybrid (100) generates a second optical signal by causing the local light to interfere with the received optical signal with a second phase difference shifted by ? from the first phase difference. Two photoelectric conversion elements (150) photoelectrically convert the first optical signal and the second optical signal, respectively, and generate a first electrical signal and a second electrical signal. A differential trans-impedance amplifier (200) includes a direct-current component correction unit (210), a trans-impedance circuit (240), and a variable gain amplifier (250).

Abstract: The present invention relates to an optical communication module, which includes: a first bidirectional multiplexer; a second bidirectional multiplexer; an optical fiber for connecting the first bidirectional multiplexer and the second bidirectional multiplexer to each other; one or more first light emitting devices connecting to the first bidirectional multiplexer, and operating in a first light emitting wavelength band; one or more first light receiving devices connecting to the first bidirectional multiplexer, and operating in a first light receiving wavelength band; one or more second light receiving devices connecting to the second bidirectional multiplexer, and operating in a second light receiving wavelength band; and one or more second light emitting devices connecting to the second bidirectional multiplexer, and operating in a second light emitting wavelength band.

Abstract: In an optical communication system containing a primary line and backup line card, a method includes providing interfaces for the primary and backup line card, each line card including a transmitter and receiver; and selecting output from the transmitter from either the primary or back up line card including selecting the backup line card when the primary line card encounters a failure.

Abstract: The disclosure provides a long-distance box and a method for processing uplink light and downlink light of the long-distance box, uplink light and downlink light from different Passive Optical Network (PON) systems are split, the uplink light from the different PON systems is transmitted through a first optical path, and the downlink light from the different PON systems is transmitted through a second optical path; wherein the uplink light from the different PON systems is amplified by an Optical Amplifier (OA) and then output to Optical Line Terminals (OLT) of respective systems; the downlink light from different PON systems with the different wavelengths is transmitted through different optical sub-paths of the second optical path according to the wavelengths of the downlink light, and the downlink light is amplified by different Optical-Electrical-Optical (OEO) conversion devices on the different optical sub-paths and then output to Optical Network Units (ONUs) of the respective systems.

Abstract: A system and method for optical switching of networks in a multi-node computing system with programmable magneto-optical switches that enable optical signal routing on optical pathways. The system includes a network of optical links interconnecting nodes with switching elements that are controlled by electrical control signals. Data transmission is along the optical links and an optical pathway is determined by the electrical control signals which are launched ahead of optical signal. If links are available, an optical pathway is reserved, and the electrical signal sets the necessary optical switches for the particular optical pathway. There is thereby eliminated the need for optical-electrical-optical conversion at each node in order to route data packets through the network. If a link or optical pathway is not available the system tries to find an alternative path. If no alternative path is available, the system reserves buffering. After transmission, all reservations are released.

Abstract: A method and system for transient and switching stabilization of a fiber optic transport system. One or more data-bearing channels are coupled to an optical fiber. The data-bearing channels are distributed among a plurality of frequency sub-bands. A set of control channels is also coupled to the optical fiber. Each control channel includes a pair of signals at separate frequencies. There is at least one control channel in each of the plurality of frequency sub-bands. The pair of signals of a control channel are cross-polarized. Optical power in at least one of the plurality of sub-bands is measured. Responsive to the measured optical power, the optical power of a control channel is adjusted to maintain a substantially constant power of a sub-band that contains the adjusted control channel.

Abstract: An optical line terminal which includes an observing unit that observes information of any one or all of an arrival interval of frames, an instantaneous bandwidth under use of a flow, a queue length of a queue temporarily storing the frames, and a traffic type, and a stop determining unit that dynamically determines a sleep time to be a period in which a sleep state where partial functions of the ONU are stopped is maintained, on the basis of the information obtained by the observing unit. The ONU is entered into a sleep state, immediately after communication ends, after a predetermined waiting time passes from when the communication ends, or after a waiting time determined on the basis of the information passes from when the communication ends.

Abstract: There is provided a method in a wavelength convertible flexible optical wavelength-division multiplexing (WC-FWDM) network. The network has a plurality of optical nodes interconnected by a plurality of optical fibers. The network is for providing an overall spectrum divisible into a set of consecutive wavelength slots. At least one optical node has at least one wavelength converter for wavelength conversion. The method includes determining a channel route through the network commencing at a source node and ceasing at a destination node. The determined channel route is selectively tunable responsive to selected ones of a plurality of routing methods. The routing methods are so selected responsive to a routing policy having one or more objectives of minimization of channel blocking, minimization of a number of wavelength converters used in the network, and minimization of physical distance traversed by a channel, and minimization of operating wavelengths of a channel.

Abstract: A method of providing routes through heterogeneous subsystems in an optical network is disclosed, which includes generating, using a processing device, a reachability matrix based on subnetwork information; and generating, using the processing device, a topology associated with the optical network using the reachability matrix. The method also includes determining, using the processing device, a shortest path through the optical network using the reachability matrix and a cost model graph; and displaying, using a graphical user interface, subsystems associated with the shortest path, regeneration locations associated with the shortest path, wavelengths associated with the shortest path, the topology, and the shortest path. Corresponding apparatus and computer-readable storage media are also disclosed.