| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a WDM optical transmission system which can reduce influence of an error in measurement of span loss and control optical amplification fast with high precision, and to provide an optical amplifier. <P>SOLUTION: In this WDM optical transmission system, wavelength number information and signal output level information of WDM signal light output from an upstream-side optical amplifying unit 30 to a transmission fiber 1 are transmitted to a downstream-side optical amplifying unit 50 by using monitor control light. The downstream-side optical amplifying unit 50 calculates loss (span loss) of the transmission line fiber 1 by using upstream-side signal output level information and downstream-side signal input level information and calculates a gain to be set to the downstream-side optical amplifier 51 based upon the loss, corrects the gain based upon the difference between a target value of a signal output level calculated by using the wavelength number information and a measured value, and controls the optical amplifier 51 according to the gain after correction. <P>COPYRIGHT: (C)2008,JPO&INPIT |
