简介 |
PROBLEM TO BE SOLVED : To provide a method and a device for controlling the difference of gain between optical signals in an optical amplifier comprising a rare earth doped fiber optically amplifying a wavelength multiplexing signal, and that for controlling output of individual optical signal.
SOLUTION : An exciting light from a light source 14 is made incident to an erbium-doped fiber 12, together with a control light, having a wavelength in the wavelength region in which the erbium doped fiber 12 shows an optical amplification action, from a light source 40. The outputs of the signal lights are detected by photodetecters 24 and 26, respectively, and inlet power of the control light is controlled based thereon. |