Optical component, optical amplifier and method of controlling optical amplifier characteristic

An optical amplifier operable to obtain an optically amplified signal by optical amplification of an input light signal and to output the optically amplified signal as an output optical signal, said optical amplifier comprising:

• an optical system comprising a plurality of optical components including an optical amplification medium, at least one of said optical components being an optical component body located on an optical path and having an optical characteristic of a prescribed type that depends on temperature;
• a characteristic control circuit operable to generate and output a temperature control signal;
• and
• a temperature adjustment member for adjusting the temperature of said optical component body to an adjustment temperature based on the temperature control signal outputted by said characteristic control circuit;
• wherein said characteristic control circuit comprises
• an optical characteristic monitoring section at a prescribed position on the optical path operable to detect quality information that expresses the quality of the optical characteristic of the prescribed type of said optical component body, and for generating a detection output indicative of the detected quality information, and
• a characteristic control section operable to generate the temperature control signal by utilizing the detection output from said optical characteristic monitoring section,
• wherein said optical characteristic monitoring section comprises a construction operable to detect as the quality information the power of the light before the light has passed through said optical component body.

A method of controlling a quality of an optical characteristic of an optical amplifier comprising a temperature adjustment member, and an optical system comprising an optical component having an optical component body, wherein the optical component performs optical processing on an optical signal, the optical component has the quality of the optical characteristic with respect to the optical processing, and the quality of the optical characteristic is dependent on temperature, said method comprising:

• acquiring information that represents the quality of the optical characteristic of the optical component at a current time point, wherein the acquired information is the optical power of the optical signal at a position prior to passage through the optical component;
• generating a temperature control signal based on the acquired information;
• adjusting the temperature of the temperature adjustment member to a holding temperature in response to the temperature control signal;
• and
• adjusting the optical characteristic to an optical characteristic of quality corresponding to an adjustment temperature by directly or indirectly setting the temperature of the optical component body to the adjustment temperature via the holding temperature of the temperature adjustment member.