The technology of this application relates to a fault detection method for an optical switching apparatus, a network device, and a system, to improve accuracy and efficiency of detecting whether the optical switching apparatus is faulty. The method includes sending a probe optical signal to a target path, where the probe optical signal is to be transmitted along the target path, and the target path includes at least one optical switching apparatus, receiving a plurality of reflected optical signals from the target path, where the plurality of reflected optical signals are formed after the probe optical signal is reflected by the target path, determining a target reflected optical signal in the plurality of reflected optical signals, where the target reflected optical signal is a reflected optical signal reflected by the optical switching apparatus, and determining, based on the target reflected optical signal, whether the optical switching apparatus is faulty.

An optical repeater device includes an amplifier module and a monitoring control circuit. The optical amplifier module includes an amplifier optical circuit including a plurality of amplification cores that amplify signal light propagating through different cores, and an optical amplifier control circuit that receives detection results from optical detectors at a plurality of signal light waveguide points of the amplifier optical circuit and generates a control signal directed to an excitation light source. The monitoring control circuit includes a reception unit that receives monitoring control channel light, a transmission unit that transmits the monitoring control channel light, an information determination unit that determines whether the monitoring control information received from the reception unit is for its own device or for another device, and a monitoring control unit that receives monitoring control information from the other device via the reception unit and the information determination unit and transmits the monitoring control information of its own device to the other device via the transmission unit and the information determination unit.

A system and method for communicating supervisory information between amplifier nodes in an optical communication network utilizes modulation of an included pump source to superimpose the supervisory information on through-transmitted customer signals (or ASE associated with the amplifier if no customer traffic is present). The supervisory information (which may include monitoring messages, provisioning data, protocol updates, and the like) is utilized as an input to an included modulator, which then forms a drive signal for the pump controller. In a preferred embodiment, binary FSK modulation is used.

A system for communicating supervisory information between amplifier nodes in an optical communication network utilizes modulation of an included pump source to superimpose the supervisory information on data signals (typically customer data signals) propagating between the amplifier nodes transmitted customer signals. The modulated pump appears as a modulated envelope on the amplified data signal exiting the amplifier node, and may be recovered by suitable demodulation components located at the second node (i.e., the destined receiver of the supervisory information). The supervisory information may include monitoring messages, provisioning data, protocol updates, etc., and is utilized as an input to an included modulator, which then forms a drive signal for the pump controller.

The invention relates to a device and a method performed by the device of monitoring an optical fibre link. The method provided for monitoring an optical fibre link comprises generating a monitoring signal used for monitoring the optical fibre link, combining the generated monitoring signal with a data signal to be transmitted over the optical fibre link, detecting backscattering of the monitoring signal from the optical fibre link, comparing the detected backscattered monitoring signal with an estimated monitoring signal backscattered along the optical fibre link, and determining, based on the comparison, at least one location along the optical fibre link where the monitoring signal is backscattered, and signal loss caused by the backscattering.

A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.

A method for determining timing information in an optical communication link includes transmitting a falling edge from a transceiver positioned at a near end of the optical communication link and simultaneously starting a first timer at the transceiver positioned at the near end of the link. The transmitted falling edge is received at a transceiver positioned at a far end of the link. A falling edge is transmitted from the transceiver positioned at the far end of the link after a response delay. The transmitted falling edge is received at the transceiver positioned at the near end of the link while the first timer is simultaneously terminated at the transceiver positioned at the near end of the link and the elapsed time is recorded. The total link delay is determined based on the elapsed time.

The present invention relates to a method for optimizing performance of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to an associated optical amplifier. Gain and output power of the associated optical amplifier are respectively controlled independently. An amplifier noise figure respectively depends on the gain of the associated optical amplifier, with each associated optical amplifier further connected to launch optical signals into a remainder of a corresponding optical transmission line. The method includes the steps of for each span, computing the amplifier noise figure and a non-linear noise generated in the span based on information about the span and using the computed amplifier noise figure and the computed non-linear noise to compute an optimum launch power, and optimizing performance of the multi-span optical fiber network based on the computed optimum launch powers of all spans.

To generate, in an optical transmission device, a response signal corresponding to executed control even when said optical transmission device does not comprise one or both of a main signal photoelectric conversion function and a main signal optical amplification function, an optical transmission device comprises: an extraction unit that outputs, from a first optical signal including a main signal and a control signal, a signal including control information included in the control signal; a control unit that executes control on the basis of the control information; and a response signal output unit that outputs, according to the control, a response signal in a wavelength band different from the main signal.

A test and measurement device has a connection to allow the test and measurement device to connect to an optical transceiver, one or more processors, configured to execute code that causes the one or more processors to: initially set operating parameters for the optical transceiver to average parameters, acquire a waveform from the optical transceiver, measure the acquired waveform and determine if operation of the transceiver passes or fails, send the waveform and the operating parameters to a machine learning system to obtain estimated parameters if the transceiver fails, adjust the operating parameters based upon the estimated parameters, and repeat the acquiring, measuring, sending, and adjusting as needed until the transceiver passes. A method to tune optical transceivers includes connecting a transceiver to a test and measurement device, setting operating parameters for the transceiver to an average set of parameters, acquiring a waveform from the transceiver, measuring the waveform to determine if the transceiver passes or fails, sending the waveform and operating parameters to a machine learning system when the transceiver fails, using the machine learning system to provide adjusted operating parameters, setting the operating parameters to the adjusted parameters, and repeating the acquiring, measuring, sending, using, and setting until the transceiver passes.