Abstract: A method and apparatus for performing path protection for rate-adaptive optics is provided. As part of the method, an aggregate input bit stream is received. The aggregate input bit stream is then transmitted using a rate-adaptive optical transceiver when transmitting on a first optical path. When the first optical path has a fault, the aggregate input bit stream is then transmitted on a second optical path using the rate-adaptive optical transceiver and a fixed-rate optical transceiver.

Abstract: An optoelectronic packet switch comprising: switch input(s) for receiving optical packet signals; a passive optical router; a control unit; and a plurality of detector-remodulators (DRMs) configured to receive signals from the switch input(s) and to generate modulated optical signals for transmission to the input ports of the passive optical router. Each DRM comprising: detector(s) for converting an optical packet-signal received at the switch input(s) into an electrical packet-signal; modulator(s) for generating the modulated optical signals.

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 device and a method are provided for merging a plurality of optical components associated with one wavelength into an optical component associated with the wavelength. The merging device includes, for each optical component of the plurality of components for merging: an optical element arranged to switch to a blocking position for blocking the optical component for merging, as a function of a blocking signal; a duplication element arranged to duplicate the optical component for merging for sending to combination element. The combination element is arranged to obtain the blocking signal by combining the duplicated optical components of the plurality of components other than the optical component for merging. A merging element is arranged to merge the optical components output by the optical element. The merging device may be integrated in an optical combiner of optical signals.

Abstract: A system includes an optical power meter operable to generate an optical power signal corresponding to the optical power of a received output signal generated by an optical IQ-modulator. The system further includes a processor operable to receive the optical power signal and determine, based on a minimization algorithm and the received optical power signal, a first bias voltage to be applied to a first sub-modulator of the optical IQ-modulator and a second bias voltage to be applied to a second sub-modulator of the optical IQ-modulator. The system may also include a peak power meter operable to generate a peak power signal corresponding to the peak power of the received output signal generated by the optical IQ-modulator, wherein the processor is further operable to determine, based on a minimization algorithm and the received peak power signal, a third bias voltage to be applied to a phase shift component of the optical IQ-modulator.

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 optical receiver receives coherent light. The optical receiver includes an amplitude adjuster, a signal processor, and a controller. The amplitude adjuster adjusts amplitude of an input signal to output an analog signal. The signal processor receives a digital signal generated from the analog signal output from the amplitude adjuster, extracts clock components from the digital signal, and after establishing synchronization between the clock components and data components, extracts the data components from the digital signal to process the data components. The controller sets amplitude of the analog signal to first amplitude before establishment of synchronization by the digital signal, and changes the set amplitude to second amplitude that is smaller than the first amplitude after the establishment of synchronization.

Abstract: An optical network unit includes a transmit/receive port and a silicon waveguide optically coupled to the transmit/receive port. The optical network unit also includes a tunable filter coupled to the silicon waveguide and providing a first output for a first frequency band and a second output for a second frequency band. The optical network unit further includes a polarization diverse receiver coupled to the tunable filter and a laser coupled to the tunable filter.

Abstract: An object of the invention is to provide an optical transmission apparatus capable of reducing the influence of nonlinear effect of an optical fiber, suppressing a band requested to a device from being widened, easily bias controlling a modulator, and flexibly switching plural modulation methods. An optical transmission apparatus 301 according to the invention includes a modulator 101 and a controller 102. The modulator 101 is a modulator capable of quadrapture phase-shift keying the light from a light source and outputting the light. The controller 102 controls the input signal to the modulator 101 and causes the modulator 101 to carry out a quadrapture phase-shift keying operation or a ?/2 shift binary phase-shift keying operation.

Abstract: The length of the optical fiber section under tension expands by a certain amount that is proportional to the level of tension applied to it. Monitoring the variations in the phase of the arriving signal allows to discover a fiber that is subject to a certain level of mechanical tension. With the method and apparatus according to the present invention it is possible to protect optical communication channels against failures in an optical transmission fiber that are caused by any kind of mechanical disturbances.

Abstract: The present invention relates to a node of an optical network, methods and service edge hub devices attachable to an optical network carrying data traffic comprising data information on a number of optical wavelength channels in one or more optical fibers. said hub device comprising one or more optical ports connectable to one or more service equipment arrangements for digital processing the received data information, the hub comprising a wavelength switching means configured to connect each channel to the ports, wherein the wavelength switching means comprises an optical splitter arrangement for spreading and directing the channels to the different ports, in one direction, and network ports, in the other direction.

Abstract: A system for delivering multiple passive optical network services is disclosed. The system includes a first optical transmission service comprising a common wavelength pair routed from a source to each of a plurality of subscribers. The system further includes a second optical transmission service comprising a plurality of unique wavelength pairs, where each of the unique wavelength pairs is routed from the source to a subscriber among the plurality of subscribers. The system delivers the first optical transmission service and the second optical transmission service to the subscriber on a single optical fiber.

Abstract: In a method for optically transmitting data by means of a pulse-width-modulated light source (LED), a pulse duty factor (N) of a pulse width modulation is specified to set the brightness of the light source (LED). A bright time (T) is divided into at least a first and second partial bright time using at least one blanking so that the data (DATA) to be transmitted are encoded by the start and time length of the at least one blanking. The sum of the partial bright times within the pulse width modulation cycle substantially corresponds to the bright time according to the specified pulse duty factor.

Abstract: A method comprising receiving a coaxial network unit (CNU) registration request from a CNU via a coaxial portion of a network, wherein the registration request is addressed to an optical line terminal (OLT), and forwarding the CNU registration request to the OLT via an optical portion of the network. Included is an OLT comprising a processor configured to receive a registration request including a logical node identifier (LNID) assigned to a coaxial line terminal (CLT) in a payload of the registration request, wherein the CLT intermediates between the OLT via an optical portion of a unified optical-coaxial network and a CNU via an electrical network portion of the unified optical-coaxial network, assign a logical link identifier (LLID) to the CNU, and send the LLID to the CNU via the CLT.

Abstract: In general, a wavelength division multiplexed (WDM) communication system simultaneously pre-filters and combines groups of wavelengths with orthogonal polarizations to provide a pre-filtered, pair-wise orthogonal aggregate WDM optical signal. In particular, an orthogonally-combining interleaving filter multiplexer provides substantially orthogonal polarizations for odd and even channel wavelengths and simultaneously pre-filters and combines the orthogonally polarized odd and even channel wavelengths using interleaver optics. The orthogonal polarizations may be provided by orientation of PM input fibers or by a polarization rotator in the orthogonally-combining interleaving filter multiplexer.

Abstract: An all-optical modulator includes a directional coupling unit that multiplexes, on a carrier light beam, a signal light beam of a modulation signal that a carrier signal at a characteristic frequency is modulated with an information signal. The all-optical modulator includes a nonlinear medium that cross-phase-modulates the carrier light beam with the multiplexed signal light beam, and frequency-multiplexes the information signal in the signal light beam on the carrier light beam to generate an optical frequency division multiplexed signal. The all-optical modulator includes a monitoring control unit that controls a polarization control unit that controls a polarization state of the signal light beam in a direction in which an intensity of a modulation component takes a maximum value, based on the intensity of the modulation component involved in a modulation signal at a desired characteristic frequency of the optical frequency division multiplexed signal.

Abstract: Systems and methods are provided for a low frequency AC comparison circuit. The low frequency AC comparison circuit includes circuitry configured to receive a monitoring signal generated by an optical detector, the monitoring signal being proportional to an amount of light generated by an optical transmission device that transmits based on a data signal that is received by an optical driver. The comparison circuit is further configured to generate a modulation current control signal that is transmitted to the optical driver based on a comparison of a low frequency AC component of the monitoring signal and a correlated low frequency AC component of the data signal.

Abstract: A light device includes a light source that irradiates light to the outside; a positional information transmission part that transmits positional information of the light device to a wireless terminal; a terminal information reception part that receives identification information of the wireless terminal and the positional information from the wireless terminal that has received the positional information; a terminal information transmission part that transmits the identification information and the positional information to a management server that manages a position of the wireless terminal; and a voltage conversion part that converts a voltage of power supplied from an external power source and supplies the power to the positional information transmission part, the terminal information reception part and the terminal information transmission part.

Abstract: A method of transporting a client signal across an optical transport network (OTN) comprises dividing a received client signal into a plurality of parallel signals at a lower bit rate. The parallel signals are mapped into a respective number of optical data units (ODUs), each ODU having payload bytes and overhead bytes. Each ODU is mapped into a respective optical transport unit (OTUs) having payload bytes and overhead bytes. The OTUs are transmitted across respective optical carriers of a super-channel, the optical carriers of the super-channel being synchronously modulated. Optical channel control information is inserted into the overhead bytes of the ODU and/or OTU. The optical channel control information is used to manage and/or control the transport of the client signal using the super-channel.

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.