The function of each component of an optical transmission device is as follows. The wavelength selecting means has a means for selecting an optical signal, and a means for outputting a signal after adjusting the signal level. The optical amplifying means amplifies the wavelength multiplexed signal having the adjusted signal level. The measuring means measures the spectrum of the amplified wavelength multiplexed signal. The setting means sets a spectrum shape, which serves as a reference of the wavelength multiplexed signal to be outputted to the transmission line, as output spectrum setting information. The control means compares the measured spectrum with the output spectrum setting information and determines the attenuation amount when adjusting the signal level for each wavelength of the wavelength multiplexed signal in the wavelength selecting means. The wavelength selecting means adjusts the signal level on the basis of the determined attenuation amount.

Systems and methods are provided for controlling one or more optical amplifiers of a C+L band photonic line system of a telecommunications network in which C-band signals and L-band signals may be transmitted. In one implementation, a control device may include a processing device and a memory device configured to store a traffic managing module for controlling C-band and the L-band traffic in the photonic line system. The traffic managing module, when executed, may be configured to cause the processing device to calculate a gain correction profile based on a difference between a saved baseline transmission profile and a measured transmission profile of a surviving band of a photonic line system when another band of the photonic line system is missing or impacted. The traffic managing module is configured to apply the gain correction profile to a respective optical amplifier of the photonic line system to compensate for the difference.

Systems and methods for characterizing an optical fiber performed in part by an optical node (12) in an optical line system (10) include performing one or more measurements to characterize the optical fiber (16, 18) with one or more components (50, 52) at the optical node (12), wherein the one or more components (50, 52) perform functions during operation of the optical node (12) and are reconfigured to perform the one or measurements independent of the functions; and configuring the optical node (12) for communication over the optical fiber (16, 18) based on the one or more measurements. The one or more components can include any of an Optical Service Channel (OSC), an Optical Time Domain Reflectometer (OTDR), and an optical amplifier. The configuring can include setting a launch power into the optical fiber based on the one or more measurements.

An optical reception apparatus (1) of the present invention includes: a local oscillator (11) outputting local oscillation light (22); an optical mixer (12) receiving a multiplexed optical signal (21) and the local oscillation light, and selectively outputting an optical signal (23) corresponding to the wavelength of the local oscillation light from the multiplexed optical signal; a photoelectric converter (13) converting the optical signal (23) output from the optical mixer into an electric signal (24); a variable gain amplifier (15) amplifying the electric signal (24) to generate an output signal (25) whose output amplitude is amplified to a certain level; a gain control signal generating circuit (16) generating a gain control signal (26) for controlling the gain of the variable gain amplifier (15); and a monitor signal generating unit (17) generating a monitor signal (27) corresponding to the power of the optical signal (23) using the gain control signal (26).

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

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.

An optical reception apparatus (1) of the present invention includes: a local oscillator (11) outputting local oscillation light (22); an optical mixer (12) receiving a multiplexed optical signal (21) and the local oscillation light, and selectively outputting an optical signal (23) corresponding to the wavelength of the local oscillation light from the multiplexed optical signal; a photoelectric converter (13) converting the optical signal (23) output from the optical mixer into an electric signal (24); a variable gain amplifier (15) amplifying the electric signal (24) to generate an output signal (25) whose output amplitude is amplified to a certain level; a gain control signal generating circuit (16) generating a gain control signal (26) for controlling the gain of the variable gain amplifier (15); and a monitor signal generating unit (17) generating a monitor signal (27) corresponding to the power of the optical signal (23) using the gain control signal (26).

A transimpedance amplifier converts an input current to a differential signal and outputs the differential signal. The transimpedance amplifier includes a single-ended amplifier configured to convert a current signal to a voltage signal, a first feedback circuit configured to generate a bypass current, a differential amplifier circuit configured to generate the differential signal in accordance with the difference between the voltage signal and a reference voltage signal, and a detector circuit configured to detect a start and an end of a burst optical signal. The detector circuit detects the end of the burst optical signal based on a peak value of the positive-phase component and a peak value of the negative-phase component and switches the time constant of the first feedback circuit from a first time constant to a second time constant smaller than the first time constant in response to detecting the end of the burst optical signal.

An optical power and gain detection apparatus including multiple optical power detection circuits, an FPGA device, and a temperature detection circuit. Various optical power detection circuits include a respective independent photoelectric converter, a trans-impedance amplifier, an analog signal conditioning circuit, a filter and an analog-digital conversion chip. By improving an analog circuit, digital detection and control in an optical amplifier, the property of the FPGA device may be used to realize the detection of optical signal and gain in a burst mode, avoid increasing complicated analogue circuits, and avoid the influence caused by element inconsistency in an analogue control solution. Whether the optical signal is in a stable mode or in a burst mode, the algorithm can detect the optical power accurately and stably, with a wide application range. By strictly controlling the synchronism of ADC sampling and the delay of calculation, the amplifier gain may be calculated more accurately.

The function of each component of an optical transmission device is as follows. The wavelength selecting means has a means for selecting an optical signal, and a means for outputting a signal after adjusting the signal level. The optical amplifying means amplifies the wavelength multiplexed signal having the adjusted signal level. The measuring means measures the spectrum of the amplified wavelength multiplexed signal. The setting means sets a spectrum shape, which serves as a reference of the wavelength multiplexed signal to be outputted to the transmission line, as output spectrum setting information. The control means compares the measured spectrum with the output spectrum setting information and determines the attenuation amount when adjusting the signal level for each wavelength of the wavelength multiplexed signal in the wavelength selecting means. The wavelength selecting means adjusts the signal level on the basis of the determined attenuation amount.