Optical amplifier, method for compensating for temperature dependency of gain flatness of an optical amplifier, and optical transmission path including optical amplifier

摘要

An optical amplifier has a gain flatness which is maintained to be substantially constant regardless of temperature changes. The optical amplifier includes an EDF amplifying section (2) and a Raman amplifying section (1), the Raman amplifying section (1) having a temperature dependent gain profile which enables compensating for the temperature dependent gain profile of the EDF amplifying section (2). The Raman amplifying section (1) includes a wavelength lock grating (8) whose transmission wavelengths shift toward the short wavelength side as the temperature increases. The wavelength lock grating (8) is preferably disposed to have the same temperature as that of an EDF (11) of the EDF amplifying section (2). A method for compensating for temperature dependency of gain flatness of an optical amplifier and an optical transmission path including an optical amplifier are also disclosed.