| 摘要 |
PROBLEM TO BE SOLVED: To provide a multistage-amplifying optical transmission system, capable of well maintaining transmission characteristics, such as an SN ratio, a waveform distortion, and to provide an optical amplifier. SOLUTION: A signal light supplied from a transmitter 100 is amplified successively through each stage of optical amplifiers 310<SB>1</SB>to 310<SB>N</SB>and also the transmitting optical fibers 810<SB>1</SB>to 810<SB>N</SB>that make up relay transmission lines. In each stage of optical amplifiers 310<SB>1</SB>to 310<SB>N</SB>, an input light monitor section 313 detects a power level of the input light; and a gain adjustment section 315 determines the gain, based on the information regarding the detected results, the amplification characteristics of an optical amplifying section, the power-level target value of an output signal light stored in a amplification information input section 314, etc., and adjusts the intensity of an excitation light supplied from an excitation section 312 to attain the determined gain. Thus, amplification at the determined gain is executed and a light of the power level substantially equal to the power-level target value of the output light is output from each stage of the optical amplifiers 310<SB>1</SB>to 310<SB>N</SB>. COPYRIGHT: (C)2005,JPO&NCIPI |
