Abstract: Disclosed is a self-coherent receiver based on single delay interferometer, comprising a first beam splitter, a first circulator, a second circulator, a double path bidirectional multiplexing delay interferometer, a first balanced detector, a second balanced detector and an electrical signal processing module.

Abstract: When a frequency deviation compensation amount is compensated for by use of frequency shift, a phase offset occurs between adjacent input blocks included in a plurality of input blocks as divided, with the result that an error occurs in a reconstructed bit sequence. A frequency deviation compensation system of the invention is characterized by comprising: a frequency deviation compensation means for compensating for a frequency deviation occurring in a signal by use of frequency shift; and a phase offset compensation means for compensating for a phase offset occurring, in the signal, due to the frequency shift.

Abstract: A method includes receiving Bell pairs. Photons are obtained in a Greenberger-Horn-Zeilinger (GHZ) state by providing, to a first beam splitter, a photon from a first Bell pair and a photon from a second Bell pair. The first beam splitter is coupled with a first output channel and a second output channel. Obtaining the photons in the GHZ state further includes providing, to a second beam splitter, a photon from a third Bell pair and a photon from a fourth Bell pair. The second beam splitter is coupled with a third output channel and a fourth output channel. Obtaining the photons in the GHZ state further includes providing a photon output from the second output channel as a first input to a detector and a photon output in the third output channel a second input to the first detector.

Abstract: A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

Abstract: An optical emitter comprising a primary laser and a plurality of secondary lasers wherein each secondary laser is optically injection locked to said primary laser, the emitter further comprising at least one polarisation controller configured to control the polarisation of the output of at least one of the secondary lasers, the emitter further comprising a combination unit that is configured to combine the outputs of the secondary laser modules into an output signal.

Abstract: An adiabatic coupling phase modulation module has an optical substrate, an asymmetric adiabatic coupling polarization beam splitter and two electro-optical phase modulators. The asymmetric adiabatic coupling polarization beam splitter performs band spatial filtering on a quantum light source signal to output a light source signal of a specific wavelength band, and performs polarization spatial filtering on the light source signal of specific wavelength band to output a first orthogonal polarization direction light source signal of the specific wavelength band and a second orthogonal polarization direction light source signal of the specific wavelength band. The two electro-optical phase modulators respectively perform phase coding processes on the first orthogonal polarization direction light source signal and the second orthogonal polarization direction light source signal.

Abstract: Techniques for identifying sources of degradations within a PON include detecting a degradation pertaining to a segment of the PON and comparing the drift over time of an optical profile of the segment with respective drifts over time of optical profiles of one or more other PON segments, where pairs of segments share respective common endpoints and an optical profile of a segment corresponds to the characteristics of optical signals delivered over the segment (e.g., attenuation, changes in frequencies, changes in power outputs, etc.). The differences between the compared drift(s) over time are utilized to narrow down the candidate components (e.g., segment endpoints, optical fibers, etc.) for the source of the degradation, and may be utilized to particularly identify a particular endpoint or optical fiber as being the source. The source of the degradation may or may not be a component of the segment to which the degradation pertained.

Abstract: A resource allocation method is provided for a non-orthogonal multiple access distribution of access network users communicatively coupled to a single transport medium. The method includes steps of allocating a first frequency and time domain resource to a first user and a second frequency and time domain resource to a second user of the access network users, obtaining channel information regarding a particular communication channel of the access network for which resources are allocated, grouping the first user with the second user based on an overlap of the first frequency and time domain resource with the second frequency and time domain resource, and assigning the first user to a different power allocation resource than the second user within the frequency and time domain overlap.

Abstract: In the present disclosure, a wireless base station apparatus sends out continuous light having a predetermined characteristic to a wireless terminal apparatus, and the wireless terminal apparatus selects authentication information corresponding to the predetermined characteristic, and transmits the authentication information to the wireless base station apparatus by RF wireless. When confirming that the received authentication information matches authentication information corresponding to the predetermined characteristic, the wireless base station apparatus permits information communication between the wireless terminal apparatus and an upper network.

Abstract: A system including optical devices is provided. The system includes a first substrate and a first device for optical communication. The first device has a first surface, a second surface opposite to the first surface, and a first side contiguous with the first surface and the second surface. Moreover, the first side is smaller than one of the first surface and the second surface in terms of area. The first device is attached at the first side thereof to the first substrate.

Abstract: A first optical communication device is provided with a laser light source 3 for emitting communication light CL and a transmitting optical fiber 11 arranged in water WA and having a light incident end portion 14 on which the communication light CL is incident. The transmitting optical fiber 11 transmits the communication light CL incident on the light incident end portion 14 toward the tip end portion 15. The transmitting optical fiber 11 is provided with a core part 21 configured to transmit the communication light CL from the light incident end portion 14 toward the tip end portion 15 and a clad part 23 covering the core part, the clad part being configured to emit at least a part of the communication light CL that transmits the core part 21 from a side surface of the transmitting optical fiber 11.

Abstract: Beam locking for free space optical communication systems using vertical-cavity surface-emitting laser arrays. The method includes: transmitting a communication beam from a light source of a first free space optical unit to a detector arranged proximate to a second FSO unit, the second FSO unit having reflective elements; transmitting one or more alignment beams from the light source to the second FSO unit; reflecting the one or more alignment beams or one or more portions thereof from the one or more reflective elements; detecting the reflected one or more alignment beams or one or more portions thereof at a light sensor; and determining whether the first FSO unit is aligned with the second FSO unit or whether the at least one communication beam is affected by one or more environmental conditions based on the detection of the reflected one or more alignment beams or the one or more portions thereof.

Abstract: Methods and apparatus for piecewise addition into an accumulation register using one or more carry runway registers, where the accumulation register includes a first plurality of qubits with each qubit representing a respective bit of a first binary number and where each carry runway register includes multiple qubits representing a respective binary number. In one aspect, a method includes inserting the one or more carry runway registers into the accumulation register at respective predetermined qubit positions, respectively, of the accumulation register; initializing each qubit of each carry runway register in a plus state; applying one or more subtraction operations to the accumulation register, where each subtraction operation subtracts a state of a respective carry runway register from a corresponding portion of the accumulation register; and adding one or more input binary numbers into the accumulation register using piecewise addition.

Abstract: Example optical devices are described. One example optical device includes a receiver. The receiver includes a photodetector, a first amplifier, a second amplifier, and a controller, where the photodetector is coupled to the first amplifier, the first amplifier is coupled to the second amplifier, and the first amplifier and the second amplifier are separately coupled to the controller. The controller is configured to control a gain of the first amplifier and a gain of the second amplifier based on a preset arrival time of an optical signal and a gain intensity corresponding to the optical signal. The photodetector is configured to receive the optical signal and convert the optical signal into a current signal. The first amplifier is configured to convert the current signal into a first voltage signal. The second amplifier is configured to convert the first voltage signal into a second voltage signal.

Abstract: An optical transmitter for quantum key distribution includes a plurality of spatially separated light sources configured to emit a light signal with the same wavelength. Each light source emits a light signal with a unique encoding. A beam combiner receives the light signals from the plurality of light sources and combines the received light signals into a combined light signal. A spatial filter is optically coupled to the beam combiner and includes an aperture that receives the combined light signal and emits a filtered light signal. The aperture has an aperture diameter less than or equal to the specified wavelength. A collimator is optically coupled to the spatial filter and receives the filtered light signal and emits a collimated light signal. An output aperture receives the collimated light signal and outputs the collimated light signal as an output light signal towards an optical receiver.

Abstract: A photon entanglement system is disclosed which includes a plurality of remote nodes (Nodes Ai and Node Bi) each without a quantum memory; and a central entangling node (Node C) in both quantum and classical communication with the remote Nodes configured to provide photon entanglement therebetween, and includes a first and second broadband photon generators each adapted to generate sets of photon pairs at: i) random times within time-bins, and ii) random frequency bins, wherein one photon of each pair set is transmitted to an associated remote node over quantum channels, and a multiplexed Bell-state analyzer configured to receive another photon of the pair, wherein if the received photons arrive at about same time, then the received photons are marked as being entangled by the controller which communicates the associated time-bin to the associated remote nodes and thereby entangling their associated photons.

Abstract: The present disclosure aims to enable communication to be performed with stable quality even when a user uses a terminal while moving. In the wireless communication system according to the present disclose, a switching control unit 15 sets switching illuminance pth for maintaining illuminance of an optical signal received by a terminal 91 at requested illuminance corresponding to throughput or higher during the time until connection switching between the communication with an optical wireless access point 92 and the communication with an RF wireless access point 93 is completed, and when the received illuminance p becomes lower than the switching illuminance pth during connection with the optical wireless access point 92, the switching control unit 15 performs connection switching from the optical wireless communication to the RF wireless communication.

Abstract: A light amplification device according to an example aspect of the invention includes a wavelength demultiplexing unit configured to demultiplex the wavelength division multiplexed signal light into a plurality of wavelength bands; a plurality of light amplification media configured to amplify the plurality of pieces of demultiplexed multiplex signal light; a wavelength multiplexing unit configured to multiplex the amplified demultiplexed multiplex signal light; a plurality of excitation energy supply units configured to supply excitation energy to each of the plurality of light amplification media; and a control unit, wherein the control unit includes a wavelength multiplexing/demultiplexing control unit configured to control the wavelength demultiplexing unit and the wavelength multiplexing unit in such a way that a starting wavelength and a wavelength number become an optimum starting wavelength and an optimum wavelength number when a sum of power consumption of the plurality of excitation energy supply un

Abstract: An LED light fixture includes one or more optical transceivers that have a light support having a plurality of light emitting diodes and one or more photodetectors attached thereto, and a processor in communication with the light emitting diodes and the one or more photodetectors. The processor is constructed and arranged to generate a communication or data transfer signal.

Abstract: An LED light and communication system is in communication with a broadband over power line communications system. The LED light and communication system includes at least one optical transceiver light fixture. The optical transceiver light fixture includes a plurality of light emitting diodes, at least one photodetector, and a processor. A facility control unit is in communication with the light emitting diode light fixtures and a control server. The facility control unit is constructed and arranged to control the operation of the optical transceiver light fixtures.