Patent ID: 8054538

Claim:
A Raman amplification apparatus for Raman-amplifying light propagating along an optical transmission line, the Raman amplification apparatus comprising: a pump light source to supply pump light for the Raman amplification to said optical transmission line; a first signal wavelength light monitor to monitor first information regarding transmission and reception levels of first signal wavelength light transmitted along said optical transmission line; a second signal wavelength light monitor to monitor second information regarding transmission and reception levels of second signal wavelength light having a wavelength different from that of the first signal wavelength light and transmitted in the same direction as the first signal wavelength light along said optical transmission line, and the second signal wavelength light is monitor signal wavelength light; a memory to store first function information relating to functions for deriving a noise amount and a gain by the Raman amplification regarding the second signal wavelength light with respect to pumping light power supplied from said pump light source; and a calculator to derive a transmission characteristic of said optical transmission line based on the first information acquired by said first signal wavelength light monitor, the first information acquired by said second signal wavelength light monitor, and the first function information stored in said memory.