Abstract: A downstream bandwidth transmission method for a passive optical network includes: an optical line terminal (OLT) sends downstream bandwidth allocation information in a downstream frame to a plurality of optical network units (ONUs); where the downstream bandwidth allocation information comprises a plurality of downstream bandwidth entries for the plurality of ONUs, each downstream bandwidth entry in the downstream bandwidth allocation information comprises ONU indication information for a respective ONU and downstream bandwidth feature information for the respective ONU, such that each of the plurality of ONUs receives respective traffic data within a downstream bandwidth allocated to the respective ONU.

Abstract: An express mesh satellite network includes a plurality of satellites arranged in a constellation, each including a plurality of coherent optical modems, wherein the plurality of satellites are configured in a topology based on traffic sources and sinks on the ground where the topology includes express links where satellites are directly connected in space by the coherent optical modems based on the traffic sources and sinks. The plurality of satellites are configured to become a node in the topology when in an associated affinity area having a ground link or requiring a relay function.

Abstract: A receiver optical sub-assembly, a combo bi-directional optical sub-assembly, a combo optical module, an optical line terminal, and a passive optical network system, where the receiver optical sub-assembly includes a first transistor-outline can, where a light incident hole is disposed on the first transistor-outline can, and where a first demultiplexer, a first optical receiver, a second optical receiver, and an optical lens combination are packaged in the first transistor-outline can.

Abstract: A method in which a plurality of transmit signals are generated at data rates that are offset from each other to minimize detectable electromagnetic interference at a particular frequency. The method further includes converting each transmit signal to a corresponding optical transmit signal of a plurality of optical transmit signals for transmission via a corresponding channel of a plurality of channels of an optical network device and transmitting the plurality of optical transmit signals via respective ones of the plurality of channels for transmission on respective optical fibers.

Abstract: A transfer device installed between a host device and a plurality of OLTs in a communication system to which a network with a PON configuration including the plurality of OLTs between the host device and a subordinate device is applied, the transfer device including a frame information acquisition unit configured to monitor downstream frames input from the host device and calculate a statistical value of the downstream frames per a predetermined fixed cycle, a frame storage unit including a plurality of queues each configured to store downstream frames to be transferred to the plurality of OLTs, the frame storage unit configured to store the downstream frames input from the host device, a frame sorting unit configured to input the downstream frames to the plurality of queues in the frame storage unit, and a distribution control determination unit configured to determine the number of frames to be sequentially input by the frame sort unit to the plurality of queues based on the statistical value.

Abstract: Systems and methods for stabilizing power levels from excessive oscillations in an optical line system of a communications network are provided. A method, according to one implementation, includes the step of detecting a perturbation of an optical power level in an optical line system having a plurality of cascaded optical power controllers. The method also includes the step of determining an estimated location to which a power controller of the plurality of cascaded optical power controllers is positioned downstream of the perturbation with respect to other power controllers of the plurality of cascaded optical power controllers. Based on the estimated location to which the power controller is positioned downstream of the perturbation, the method also includes the step of providing feedback in a control loop to reduce the effects of the perturbation.

Abstract: A method for processing low-rate service data, an apparatus, and a system, where the method includes: mapping low-rate service data into a newly defined low-rate data frame, where a rate of the low-rate data frame matches a rate of the low-rate service data, the data frame includes an overhead area and a payload area, the payload area is used to carry the low-rate service data, a rate of the payload area in the low-rate data frame is not less than the rate of the low-rate service data, and the rate of the low-rate service data is less than 1 Gbps; mapping the low-rate data frame into one or more slots in another data frame, where a rate of the slot is not greater than 100 Mbps; mapping the other data frame into an optical transport unit (OTU) frame; and sending the OTU frame.

Abstract: Provided herein are various improvements to laser communication ranging. In one example, a method includes combining a ranging signal with data communications into an optical transmission for receipt by a communication node, and obtaining an additional optical transmission transferred by the communication node comprising additional data communications combined with a retransmitted version of the ranging signal. The method includes determining an indication of a range to the communication node based at least on a comparison between properties of the ranging signal and properties of the retransmitted version of the ranging signal after separation from the additional data communications.

Abstract: The present disclosure provides a method and system for configuring an optical time domain reflectometer (OTDR) in a gigabit passive optical networks (PON), characterized by the steps of: collecting network data of the network to be scanned by switch controller to characterize said network; collecting data from various optical network terminals (ONTs) of the gigabit passive optical networks (GPON) by an OTDR and the Switch Controller to form a training database, the training data is used to train the method; optimizing the parameters of the optical time domain reflectometer (OTDR) based on the network data and the training database by a processor provided on the switching controller using machine learning. For point-to-multipoint (PMP) networks such as PON, the present method and system provides optimal set of parameters to configure OTDR before performing trace.

Abstract: An optical transmission device of each node simultaneously sends a plurality of signals having different wavelengths as delay measurement signals to a transmission path. The optical transmission device determines a delay value that reflects a propagation delay calculated based on an arrival time difference between a plurality of wavelengths in a signal received from another node, and determines a waiting time amount based on the delay value and the propagation delay. The optical transmission device notifies the other node of the delay value. Each optical transmission device outputs the received signal from the other node with a delay of the waiting time amount. The optical transmission device generates an optical intermittent signal obtained by selecting and multiplexing any of time information, the delay measurement signal, and communication information. A reception side extracts a desired multiplexed signal from the received optical intermittent signals.

Abstract: An optical receiver is disclosed, including an optoelectronic detector, a transimpedance amplification (TIA) circuit, a single-ended-to-differential converter, an I/O interface, and a controller. The optoelectronic detector, having bandwidth lower than required system transmission bandwidth, converts an optical signal into a current signal. The TIA circuit compensate gain for the received current signal based on a received control signal, to obtain a voltage signal, where a frequency response value of the current signal within first bandwidth is greater than that within the bandwidth of the optoelectronic detector, and any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector. The single-ended-to-differential converter converts the voltage signal into a differential voltage signal. The I/O interface outputs the differential voltage signal. The controller generates the control signal based on the differential voltage signal.

Abstract: An object is to provide an optical fiber route search method, an optical fiber route search device, and a program that can efficiently confirm a path of an optical fiber that is installed over a long distance or across a large range. The optical fiber route search method according to the present invention carries out optical measurement that performs distributed measurement of the state of an optical fiber while applying a disturbance to the optical fiber in a portion in which wires of the optical fiber are parallel to each other, branch out, or intersect with each other (a proximity portion), and determines that the position in which the number of singularities (peaks or intensity fluctuations) fluctuates (becomes plural) is the position of the proximity portion from a distribution diagram obtained through the optical measurement.

Abstract: In some examples, a tunable dense wavelength division multiplexing (DWDM) optical time-domain reflectometer (OTDR) may include a fiber optic link analyzer, executed by at least one hardware processor, to determine, based on a user input, for a fiber optic link of a plurality of fiber optic finks of a fiber optic cable, whether the fiber optic fink is active or not active. The DWDM OTDR may specify, based on a determination that the fiber optic fink is active, a test wavelength that is different from a data transmission wavelength of data transmitted by the fiber optic fink. A DWDM multiplexer may be collocated with the DWDM OTDR to selectively connect, based on the specified test wavelength, the DWDM OTDR to the fiber optic fink of the plurality of fiber optic links for testing of the fiber optic link.

Abstract: Device cost and electric power consumption are reduced. Nodes 11a to 11d as optical add/drop multiplexers each include cAWGs 24a and 24b that include a plurality of first side ports and a plurality of second side ports connected between light transmission paths as optical fibers 12 and 13 and transponders 25a to 25n and in which a first optical signal input-output channel interval of each port is a plurality of times larger than a second optical signal input-output channel interval of ports of the transponders 25a to 25n and optical signals of a plurality of different wavelengths from one or a plurality of transponders 25a to 25n or the light transmission paths can pass through a first channel. The cAWGs 24a and 24b cause the optical signals from the transponders 25a to 25n to pass through the first side ports, and then cyclically outputs and transmits the optical signals through the plurality of second side ports in a predetermined order to the light transmission paths.

Abstract: Methods, devices, and systems are described for free space optical communication. An example method can comprise generating a first linearly polarized optical signal and converting the first linearly polarized optical signal to a first circularly polarized optical signal. The first circularly polarized optical signal can be output into free space. The method can comprise converting a second circularly polarized optical signal, received via free space, to a second linearly polarized optical signal. The second linearly polarized optical signal can have a linear polarization different than a polarization of the first linearly polarized optical signal. The method can comprise directing, via a polarizing beam splitter, the second linearly polarized optical signal to a first path separate from a second path from which the polarizing beam splitter received the first linearly polarized optical signal.

Abstract: A method for routing in a quantum network is provided. The method may include receiving parameters including a fidelity with coherence decay time and an entanglement generation rate for each quantum node in a mesh quantum network by a controller, the controller being configured to communicate with each quantum node of a plurality of quantum nodes in the mesh quantum network. Each quantum node includes a quantum memory and a processor. The method may also include analyzing the fidelity with coherence decay time and the entanglement generation rate to yield a determination of a path fidelity with a path coherence decay time and a path entanglement generation rate between at least one pair of quantum nodes. The method may further include, based on the determination, selecting a quantum communication path from a source node to a destination node.

Abstract: Provided is an optical communication device including: a first channel card configured to convert an input first signal into a first optical signal and output the first optical signal to any one of a first MUX/DEMUX connected to a first optical line and a second MUX/DEMUX connected to a second optical line; a second channel card configured to convert an input second signal into a second optical signal and output the second optical signal to any one of the first MUX/DEMUX and the second MUX/DEMUX; and a controller configured to monitor states of the first optical line and the second optical line to determine a MUX/DEMUX from which the first optical signal and the second optical signal are respectively output, from among the first MUX/DEMUX and the second MUX/DEMUX.

Abstract: In some examples, fiber optic link intermittent fault detection and localization may include determining, for a fiber optic link that is to be analyzed, at least one section corresponding to the fiber optic link, at least one detection threshold corresponding to the at least one section, and a reference trace for the fiber optic link. A real-time trace may be acquired for the fiber optic link, and a comparison trace may be generated based on analysis of the reference trace and the real-time trace. Based on analysis of the at least one section to determine whether at least one section level parameter determined from the comparison trace exceeds the at least one detection threshold, an event associated with the fiber optic link may be identified.

Abstract: An ONU includes a communication unit, an abnormal light emission prevention unit, and a control unit that transmits a data signal and a transmission permission signal to the communication unit and transmits the transmission permission signal to the abnormal light emission prevention unit between a transmission start time and a transmission end time. When the transmission permission signal is received, the communication unit, transmits an optical signal to an OLT, and transmits an operation signal to the abnormal light emission prevention unit during the transmission of the optical signal. The abnormal light emission prevention unit transmits a stop signal to the communication unit when a difference between a time for which the transmission permission signal is received and a time for which the operation signal is received is greater than or equal to a threshold value. The communication unit stops when the stop signal is received.

Abstract: Methods, systems, and apparatus for performing an entangling operation on a system of qubits. In one aspect, a method includes operating the system of qubits, wherein the system of qubits comprises: a plurality of first qubits, a plurality of second qubits, a plurality of qubit couplers defining nearest neighbor interactions between the first qubits and second qubits, wherein the system of qubits is arranged as a two dimensional grid and each qubit of the multiple first qubits is coupled to multiple second qubits through respective qubit couplers, and wherein operating the system of qubits comprises: pairing multiple first qubits with respective neighboring second qubits; performing an entangling operation on each paired first and second qubit in parallel, comprising detuning each second qubit in the paired first and second qubits in parallel.