| 摘要 |
PROBLEM TO BE SOLVED: To reduce amount of surge light produced by dividing inputted optical signals into two parts and performing logical code inversion and waveform conversion on one part and coupling and amplification to the other part, and then extracting only the wavelength component of the optical signals, so that the coupled optical signals become optical signals having a fixed power level. SOLUTION: Optical signals having a wavelength 1 and inputted to an input terminal 101 are divided into two by means of an optical distributor 211, and one part is inputted to an optical coupler 207. The other part is made incident to an optical receiver 203, is converted into electrical signals of the level corresponding to the power, inverts logical codes by means of an inverting amplifier 2051, and is made into the drive signal of a light source 206. The light source 206 outputs optical signals having a wavelengthλ2 in accordance with the drive signal. After the optical signals having the wavelengthλ2 are divided into two parts by means of the optical distributor 211 and coupled with the other part of the optical signals having the wavelengthλ1 by means of an optical coupler 207, the coupled signals are made incident to an optical fiber amplifier 202 for amplification. A wavelength pass filter 209 only extracts the component having the wavelength #11 from the (coupled) light and outputs the component to the outside. When the optical signals inputted to the optical fiber amplifier is constant, the amount of surge light produced can be reduced. |
