Band identifying circuit, wavelength-multiplexed optical signal transmission device, wavelength-multiplexed optical signal transmission system, and band identifying method

A wavelength-multiplexed optical signal transmission system comprising:

• a wavelength-multiplexed optical signal transmission device including
• a plurality of optical transmitters for respectively outputting a plurality of optical signals having mutually different wavelengths,
• an optical intensity controller circuit configured to change, by a prescribed level, an optical intensity of an optical signal outputted from a target-of-identification optical transmitter among the plurality of outputted optical signals, and
• a multiplexer configured to multiplex the plurality of optical signals and output a wavelength-multiplexed optical signal;
• and
• a wavelength-multiplexed optical signal reception device including
• a receiver configured to receive the transmitted wavelength-multiplexed optical signal,
• a spectrum acquisition circuit configured to measure an optical intensity of each wavelength of the received wavelength-multiplexed optical signal and output a result of the measurement as a spectrum, and
• a band identifier circuit configured to acquire a change amount of the outputted spectrum in synchronization with an operation of the optical intensity controller circuit and identify a band occupied by the target-of-identification optical transmitter, based on the acquired change amount of the spectrum.

A band identifying method comprising:

• changing, by a prescribed level, an optical intensity of an optical signal outputted from a target-of-identification optical transmitter among a plurality of optical signals respectively outputted from a plurality of optical transmitters, constituting a wavelength-multiplexed optical signal, and having mutually different wavelengths;
• measuring an optical intensity of each wavelength of the wavelength-multiplexed optical signal and outputting a result of the measurement as a spectrum;
• and
• identifying a band occupied by the target-of-identification optical transmitter, based on a change amount of the outputted spectrum.