Patent ID: 9391426
Filing Date: 2016-07-12
CPC Classification: G02F,H01S,H04B,H04J,H04Q

Claim Text:
1. A Raman amplifier, comprising: a plurality of semiconductor lasers that respectively provide a plurality of pump light beams with different wavelengths for an optical transmission medium; a gain monitor that monitors an average Raman gain in the optical transmission medium; a storage unit that stores ratio information indicating a power ratio of the plurality of pump light beams; and a controller that controls the power of the plurality of pump light beams based on the average Raman gain monitored by the gain monitor and the ratio information, wherein the ratio information indicates the power ratio of the plurality of pump light beams to obtain a specified gain characteristic with respect to the average Raman gain in the optical transmission medium for a range between a specified lower limit average Raman gain and a specified upper limit average Raman gain, indicates a first constant ratio of power of the plurality of pump light beams for a range where the average Raman gain is lower than the specified lower limit average Raman gain, and indicates a second constant ratio of power of the plurality of pump light beams for a range where the average Raman gain is higher than the specified upper limit average Raman gain.