Patent ID: 8049955

Claim:
An optical communication apparatus comprising: an optical amplification apparatus including: a Raman amplifier that inputs pump light into an optical fiber through which an optical signal passes, to amplify the optical signal; a first optical receiving unit provided downstream of the Raman amplifier and configured to monitor power of the optical signal amplified by the Raman amplifier; a gain calculating unit that, based on the power monitored by the first optical receiving unit, calculates gain of the optical signal imparted by the pump light; a noise-power calculating unit that, based on the gain calculated by the gain calculating unit, calculates power of a noise component included in the optical signal; and an output unit that outputs the power of the noise component calculated by the noise-power calculating unit, and a power controlling apparatus that is provided downstream of the optical amplification apparatus and includes: a second optical receiving unit that monitors the optical signal amplified by the optical amplification apparatus; an erbium doped fiber amplifier; a third optical receiving unit that monitors the optical signal amplified by the erbium doped fiber amplifier; a control unit that controls the erbium doped fiber amplifier, wherein the control unit calculates gain of a signal component included in the light output from the erbium doped fiber amplifier against the input optical signal, based on power of an optical signal indicated by an electrical signal output from the second optical receiving unit, power of an optical signal indicated by an electrical signal output from the third optical receiving unit, and the power of the noise component.