Light amplification device, light transmission system, and light amplification method

A light transmission system comprising:

• a light amplification unit configured to control a wavelength band of an optical carrier wave and thereby generate band control light and amplify the band control light;
• a light detection unit configured to detect intensity of the band control light that has been amplified by the light amplification unit, and generate light intensity information;
• and
• a control unit configured to control the light amplification unit in such a way as to adjust the wavelength band, based on the light intensity information.

A light amplification method comprising:

• controlling a wavelength band of an optical carrier wave and thereby generating band control light;
• introducing the band control light into a plurality of light amplification media;
• amplifying the band control light in a coupled state in which propagation light propagating through the plurality of light amplification media induces a crosstalk;
• and
• controlling the wavelength band in such way that coherence of the band control light that has propagated through the plurality of light amplification media is reduced.