Abstract: This application discloses a submarine cable fault determining method and apparatus for realizing detecting whether a fault occurs to a submarine cable, without depending on TTE. The submarine cable fault determining method includes: receiving, by a network management system, first detection information from a first device during a first preset time, and receiving second detection information from a second device during a second preset time, where the second detection information is used to indicate whether the second device receives a first heartbeat signal from the first device through a submarine cable, and the first detection information is used to indicate whether the first device receives a second heartbeat signal from the second device through the submarine cable; and determining, by the network management system based on the first detection information and the second detection information, whether a fault occurs to the submarine cable between the first device and the second device.

Abstract: The present disclosure relates to optical communications, and in particular, to a DWDM remote pumping system for improving an OSNR. The system includes remote pumping gain unit, preamplifier, and gain flattening filter sequentially connected. Remote pumping gain unit and preamplifier are cascaded one behind the other as a whole amplifier. Gain flattening filter is disposed at the preamplifier's output end. In the system, remote gain unit and preamplifier which have large impact on the OSNR of the entire system are optimally designed as a whole amplifier. In remote gain unit, gain flattening filter originally disposed between two erbium-doped fiber segments is moved back to preamplifier's output end for significant improvement of gain and noise figures of the remote gain unit while ensuring gain flatness of the entire transmission system, thus effectively improving the entire system's OSNR, improving operation stability and reliability, effectively reducing bit error rate, and facilitating system maintenance.

Abstract: The present disclosure provides a compact-optic-connecting device for mounting on a motherboard of a computer, which includes an optic-receiving unit, an optic-launching unit, two flexible-circuit plates, a circuit board and a connecting interface. The optic-receiving unit and the optic-launching unit are connected to the bottom surface of the circuit board respectively via flexible-circuit plates. The connecting interface is connected to the bottom surface of the circuit board, and also connected to an external motherboard via the connecting interface. By virtue of such structure, the compact optic-connecting device can have a small length and size, and meanwhile to maintain a safety distance between the connecting interface and the optic-receiving unit, or the connecting interface and optic-launching unit, to prevent faulty conduction therebetween.

Abstract: A method and an apparatus for predicting a fault of an optical circuit includes determining a classification threshold of an operating parameter based on a classification sample set corresponding to the operating parameter of optical circuit and predicting, based on comparison results between the classification threshold and a plurality of measured values in a sequence, whether a fault occurs in the future on the optical circuit corresponding to the sequence.

Abstract: A method includes: generating indication information, where the indication information is used to indicate a resource allocation table corresponding to a first data unit in the plurality of data units; sending the indication information in a timeslot previous to a timeslot used to send the first data unit; and sending the plurality of data units, where a resource allocation table corresponding to each data unit is selected from a plurality of resource allocation tables in a cyclic manner, and a cyclically initial resource allocation table is the resource allocation table indicated by the indication information.

Abstract: Aspects described herein include an optical apparatus comprising a multiple-stage arrangement of two-mode Bragg gratings comprising: at least a first Bragg grating of a first stage. The first Bragg grating is configured to transmit a first two wavelengths and to reflect a second two wavelengths of a received optical signal. The optical apparatus further comprises a second Bragg grating of a second stage. The second Bragg grating is configured to transmit one of the first two wavelengths and to reflect an other of the first two wavelengths. The optical apparatus further comprises a third Bragg grating of the second stage. The third Bragg grating is configured to transmit one of the second two wavelengths and to reflect an other of the second two wavelengths.

Abstract: To use a plurality of wavelength bands, this seabed branching device comprises: a first demultiplexing unit that demultiplexes a wavelength multiplexed optical signal, which was input from a first terminal, into a first wavelength multiplexed optical signal and a second wavelength multiplexed optical signal; an optical add/drop unit that outputs at least a third wavelength multiplexed optical signal included in the first wavelength multiplexed optical signal to a second terminal station, and outputs at least a fifth wavelength multiplexed optical signal by multiplexing a fourth wavelength multiplexed optical signal included in the first wavelength multiplexed optical signal and a wavelength multiplexed optical signal input from the second terminal station; and a first multiplexing unit that multiplexes the second wavelength multiplexed optical signal and the fifth wavelength multiplexed optical signal, which was input from the optical add/drop unit, and outputs the result to a third terminal station.

Abstract: A measurement apparatus includes: a light source unit configured to generate optical signals of, from among n+1 frequencies (n is an integer of 3 or larger) at a predetermined frequency interval, n frequencies except for a target frequency, and output the generated optical signals to an optical transmission path that is a measurement target; an optical power measurement device configured to measure of an optical signal of the target frequency output from the optical transmission path and generated in the optical transmission path as a result of four-wave-mixing of the optical signals of the n frequencies; and a processor configured to determine a power spectrum density of non-linear interference noise that occurs in the optical transmission path, by multiplying the power of the optical signal of the target frequency by an adjustment value.

Abstract: A microcomputer 202 is coupled to a SFP module 101 via control signal lines 112 to 114. The microcomputer 202 monitors control signals transmitted on the control signal lines 112 to 114, and acquires, based on the result of monitoring, the condition of the SFP module 101 from a ROM 151 at a timing when a protocol chip 102 is not accessing the SFP module 101.

Abstract: A system has a plurality of non-linear circuit stages and an intervening linear circuit stage. An input signal is provided to a first non-linear circuit stage, and from the first non-linear circuit stage, to the linear circuit stage. The first non-linear circuit stage applies a second-order distortion to the input signal and provides the resulting signal to the linear circuit stage. The resulting signal that is output from the linear circuit stage is inverted with respect to the input signal and suitably linearly processed (attenuated or amplified). This signal is then provided to a second non-linear circuit that applies a second-order distortion and outputs a signal that has an overall reduction in second-order distortion.

Abstract: The various embodiments provide an optical transmission system comprising an optical transmitter configured to transmit data over an optical fiber transmission channel comprising a multi-core fiber, the data being carried by optical signals, the optical signals propagating along the multi-core fiber according to two or more cores, the multi-core fiber being associated with fiber parameters and misalignment losses values, at least one scrambling device being arranged in the optical fiber transmission channel for scrambling the two or more cores according to a scrambling function, wherein the optical fiber transmission channel comprises a system configuration device configured to determine a core dependent loss value depending on the fiber parameters, at least one misalignment loss, a number of the at least one scrambling device, and the scrambling function.

Abstract: A process of estimating a transfer function or an inverse transfer function of the optical transmitter from first data obtained by the optical receiver when a first known signal is transmitted from the transmitter to the receiver, and a temporary transfer function or a temporary inverse transfer function of the optical receiver, is performed for multiple frequency offsets between the optical transmitter and the optical receiver. At this time, the transfer function or the inverse transfer function of the optical transmitter is estimated by comparing the first data obtained by compensating at least one or none of a temporary transfer function of the optical receiver and transmission path characteristics detected in the receiver, with a first known signal before transmission to which what is not compensated for the first data between the temporary transfer function of the optical receiver and the transmission path characteristic is added.

Abstract: A converter module comprises a housing; a fiber optic connector integrated with the housing, wherein the fiber optic connector is configured to mount directly to a fiber optic connector in a service terminal; a single electrical connector configured to couple to a metallic medium; and an optical-to-electrical (O/E) converter located in the housing and coupled to the fiber optic connector and the single electrical connector, the O/E converter configured to convert between optical frames communicated via the fiber optic connector and electrical signals communicated via the metallic medium.

Abstract: An RF imaging receiver using photonic spatial beam processing is provided with an optical beam steerer that acts on the individual modulated optical signals to induce individual phase delays that produce a phase delay with a linear term, and possibly spherical or aspherical terms, across a two-dimensional wavefront of the composite optical signal to steer the composite optical signal and move the location of the spot on the optical detector array. The optical beam steerer may change the path length or a refractive index for each of the modulated optical signals to induce the requisite phase delays. The optical beam steerer may be implemented, for example, with a Risley prism or liquid crystal or MEMs spatial light modulator.

Abstract: A communication device is provided that estimates one or more disturbance values associated with one or more components of the communication device, and adjusts the communication device to change a received power of the output signal. The communication device includes a transmitter having a seed laser configured to provide an amount of bandwidth for an output signal, an Erbium-doped fiber amplifier (EDFA) configured to increase an amplitude of the output signal, and a single mode variable optical attenuator (SMVOA) configured to decrease the amplitude of the output signal.

Abstract: A device (10;150;200) is configured to receive an optical signal. The device comprises a dispersion compensator (210a) comprising a plurality of optical dispersion compensator units (220). Each optical dispersion compensator unit comprises a plurality of delay elements (20;40). The dispersion compensator (210a) is configured to selectively activate one or more of the optical dispersion compensator units (220). The dispersion compensator (210a) is configured to compensate for dispersion of the optical signal with the activated one or more optical dispersion compensator unit (200).

Abstract: A switch for switching a signal between a source client device and a destination client device, the switch includes: a switch module housing unit including a switch module, configured to output a first signal, and a second signal; a shuffle including: a first input, a first output, and a second output, wherein the first input is configured to receive the first signal and the second signal from the switch module, and to direct the first signal to the first output and the second signal to the second output. A switch including a switch module housing unit, including: a first input, a second input, and a first output, wherein the first input is configured to receive a first signal and direct it to the first output, and the second input is configured to receive a second signal and direct it to the first output.

Abstract: A system for determining a channel margin of a data transmission channel (DTC) using error correction under real-world channel conditions is described. The system includes a monitoring unit, an operating state determining unit and a data processing unit. The monitoring unit monitors data transmission along the DTC and estimates a statistical distribution of errors (H) in the transmission of data. The operating state determining unit determines a current value of an operating state parameter for the DTC. The data processing unit determines a reference channel margin associated with said current value of the operating state parameter for a reference channel and the error correction scheme employed, provides a statistical distribution of errors (HR) associated with said reference channel for said current value of said operating state parameter, compute a deviation of H and HR, and computes a reduction of the reference channel margin.

Abstract: Various embodiments for an optical system are described herein. Generally, the optical system may include an optical transmitter coupled to an optical signal transmission path, an optical receiver coupled to an optical signal reception path, and an external signal path extending between an external optical assembly and both the optical signal transmission path and the optical signal reception path. An optical polarization division multiplexer may be provided to couple the optical signal transmission path and the optical signal reception path to the external signal path. A first non-reciprocal polarization rotator may be also positioned along the external signal path between the optical polarization division multiplexer and the external optical assembly. Further, a quarter wave plate may be positioned along the external signal path between the non-reciprocal polarization rotator and the external optical assembly.

Abstract: Devices, systems and methods for encoding information using optical components are described. Information associated with a first optical signal (e.g., an optical pump) is encoded onto the phase of a second optical signal (e.g., an optical probe) using cross phase modulation (XPM) in a non-linear optical medium. The optical signals are multiplexed together into the nonlinear optical medium. The probe experiences a modified index of refraction as it propagates through the medium and thus accumulates a phase change proportional to the intensity of the pump. The disclosed devices can be incorporated into larger components and systems for various applications such as scientific diagnostics, radar, remote sensing, wireless communications, and quantum computing that can benefit from encoding and generation of low noise, high resolution signals.