An optical power compensation method and a device relating to the communications field comprises: a first node that obtains a first optical power and a first timepoint, receives at least two second optical powers sent by a second node, obtains second timepoints corresponding with the at least two second optical powers, where the second timepoint is a timepoint at which the first node receives the second optical power, and determines a target timepoint from the second timepoints according to a preset delay and the first timepoint. The first node determines a variation of a span loss according to a target optical power and the first optical power, where the target optical power is a second optical power corresponding to the target timepoint, and adjusts a gain value and/or an attenuation value of the first node according to the variation of the span loss.

A method for gain control for an optical amplifier module is provided. The method may include receiving an input light signal at a first amplifier. The method may include dynamically adjusting a gain of the input light signal based on feedback monitoring of an output light signal. The method may include receiving the gain adjusted light signal at a second amplifier for output of the optical amplifier module.

Example fiber amplifiers and gain adjustment methods for the fiber amplifiers are described. One example fiber amplifier includes a first power amplifier, a wavelength level adjuster, and a controller, where the first power amplifier and the wavelength level adjuster are sequentially connected. The controller includes a first input end and a control output end. The first input end is configured to receive an input optical signal of the fiber amplifier, and the control output end is configured to output a first amplification control signal to the first power amplifier, and output an adjustment control signal to the wavelength level adjuster. The wavelength level adjuster is configured to perform power adjustment on each wavelength based on the adjustment control signal.

Methods, apparatuses, and systems for packet detection in a point-to-point wireless communication network is disclosed. One method includes receiving, by a receiving node, a plurality of packets, adjusting, by an adjustable gain amplifier of the receiving node, a power level of the received plurality of packets, controlling, by a gain control module, a gain of the adjustable gain amplifier, thereby controlling the power level of the received plurality of packets, monitoring the controlled gain of the gain control module over a period of time, identifying a timing of reception of interfering packets based on the monitoring of the controlled gain of the gain control module over the period of time, and adjustably controlling, by the gain control module, the gain of the adjustable gain amplifier based on the identified timing of reception of the interfering packets.

Provided are a control method and system for a cascade hybrid amplifier, in which respective hybrid amplifiers in the cascade hybrid amplifier simultaneously start to implement a pump-starting process comprising: when the hybrid amplifier receives a request to start pumping, determining whether conditions are satisfied, if yes, determining stability of power of an input light of a Raman, starting pumping of an EDFA so that the EDFA enters into an APC operation mode; starting pumping of the Raman, and calculating a gain deviation according to the calculated input light powers before and after pump-starting of the Raman when no reflection alarm exists; and adjusting gain of the Raman according to the gain deviation, and switching to an AGC (automatic gain control) operation mode after the adjustment; and switching the EDFA to the AGC operation mode.

A proactive and non-obtrusive channel probing scheme is provided to accurately predict channel power, gain, and optical signal to noise ratio (OSNR) without disrupting the existing connections. In one example, using a probe signal with 5 s pulse duration in a single-hop network, rapid wavelength switching is achieved with power excursions less than or equal to 0.2 dB for different loading configurations.

This application discloses an optical power compensation method and a device, and relate to the communications field. A specific solution comprises: a first node obtains a first optical power and a first timepoint, receives at least two second optical powers sent by a second node, obtains second timepoints corresponding with the at least two second optical powers, where the second timepoint is a timepoint at which the first node receives the second optical power, and determines a target timepoint from the second timepoints according to a preset delay and the first timepoint; the first node determines a variation of a span loss according to a target optical power and the first optical power, where the target optical power is a second optical power corresponding to the target timepoint, and adjusts a gain value and/or an attenuation value of the first node according to the variation of the span loss.

A low-noise amplifier includes a gain medium and two or more amplifier stages. Each amplifier stage includes an optical filter to pass all wavelengths of a respective input optical signal in a given propagation direction over the gain medium and reflect wavelengths above a respective threshold wavelength received in the opposite direction, and a respective Raman pump to inject a pump light centered at a wavelength lower than the threshold wavelength onto the gain medium for transmission in the given direction. A first amplifier stage outputs a first combined optical signal including all wavelengths of the respective input optical signal and a pump light injected by the respective Raman pump. The second amplifier stage receives the first combined optical signal as its input and outputs a second combined optical signal including all wavelengths of the first combined optical signal and a pump light injected by the respective Raman pump.

A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

Device and methods for real-time polarization-dependent loss monitoring at coherent transceivers. In one embodiment, there is provided a method of monitoring a polarization dependent loss (PDL) of a signal during transmission through an optical communication link, the method comprising: receiving the signal by a coherent receiver, the received signal being subjected to one or more impairments in Amplifier Gain Control (AGC) mode, the one or more impairments including PDL; estimating an AGC gain effect of the AGC mode; compensating for the AGC gain effect in the received signal; determining the PDL from the compensated signal; and reporting the PDL.