A fiber-optic communication apparatus includes an optical monitor that monitors a WDM signal in. which optical signals of multiple channels are multiplexed, a processor that calculates a control value for controlling an optical power of the WDM signal, based. on a power spectrum detected by the optical monitor, in a unit interval of frequency narrower than a channel bandwidth of the WDM signal, and an optical power adjusting mechanism that adjusts the optical power of the WDM signal in the unit interval of frequency based on the control value.

Systems and methods include causing perturbations across optical spectrum; probing responses across some or all of the optical spectrum after the perturbations; and determining a nonlinear transfer function based on the responses. The nonlinear transfer function can include a representation of any of end-to-end channel powers, Signal-to-Noise Ratio (SNR), Noise-to-Signal Ratio (NSR), Bit Error Rate (BER), Q, and Mean Squared Error (MSE).

An optical receiver includes an optical amplifier that amplifies a received optical signal containing multiple wavelengths, a monitor circuit that monitors light intensities of the demultiplexed optical signal, a processor, and a memory having information representing a relationship between a total incident light intensity of the optical signal incident onto the optical amplifier and gains of the optical amplifier for the respective wavelengths. The processor repeats first calculation for determining the gains of the respective wavelengths from the memory, based on a drive current for driving the optical amplifier and an estimation value of the total incident light intensity of the optical signal, second calculation for calculating the incident light intensities of the respective wavelengths of the optical signal based on the gains and the monitored light intensities, and third calculation to calculate the total incident light intensity of the optical signal, until the total incident light intensity converges.

Systems and methods are provided for controlling one or more optical amplifiers of a C+L band photonic line system (30) of a telecommunications network in which C-band signals and L-band signals may be transmitted. In one implementation, a method (130) may execute a traffic managing module (23). When executed, the traffic managing module (23) may be configured to enable a processing device (12) to calculate (132) a gain correction profile based on a difference between a saved baseline transmission profile (84) and a measured transmission profile (94) of a surviving band of a photonic line system (30) when another band of the photonic line system (30) is missing or impacted. The traffic managing module (23) may further be configured to enable the processing device (12) to apply (134) the gain correction profile to a respective optical amplifier (46) of the photonic line system (30) to compensate for the difference.

A system for monitoring a signal on an optical fiber includes a fiber optic connector having a housing couplable to a receptacle. An optical fiber that transmits a first optical signal has first fiber core at least partially surrounded by a cladding and has a first end terminating proximate the housing. The first optical signal is transmitted along the first fiber core. An optical tap has a first tap waveguide arranged and is configured to receive at least part of the first optical signal as a first tap signal. The first tap waveguide comprises an output port for the first tap signal for directing the tap signal to a detector unit. In other embodiments, a detector unit detects light from the optical signal that is propagating along the fiber cladding.

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.

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.

An Automated Analysis and Warning of Optical Transmission (AWOT) between BBU unit and RRU of radio transmitting station accurately and quickly identifies errors on an optical transmission line, thereby reducing costs in terms of labor and equipment, and at the same time reducing service downtime of mobile communication systems.

Disclosed are an APR protection method and device, and a computer storage medium. A preamplifier PA of each of two optical amplifier units at two ends of a transmission line is connected to a booster amplifier BA of the other amplifier unit by an optical fiber. The method comprises: when a reception state of PA of at least one of two amplifier units is a loss of signal state and a switch chip of said amplifier unit detects a link interruption signal, activating an APR protection state of said amplifier unit which is to turn off BA output of said amplifier unit; when the switch chip of at least one of two amplifier units detects a link conduction signal, deactivating the APR protection state of the present amplifier unit to restore a state of BA of said amplifier unit to a state before the APR protection state is activated.

An optical power value transmission method and system, and a related device is disclosed. The method includes: A source network device obtains optical multiplexing section link information that indicates an optical fiber connection relationship between any two adjacent network devices between the source and a target network device of an optical multiplexing section which are located in different data communication networks. The source network device determines, based on the optical multiplexing section link information, a first output port that connected to a downstream network device by using a first optical fiber, and the downstream network device is connected to the source network device and that is indicated by the optical multiplexing section link information. The source network device obtains, on the first output port, a first output power value of an optical signal and sent it to the downstream network device by using the first optical fiber.