Patent ID: 7349150

Claim:
An optical terminal apparatus comprising: an optical multiplexer/demultiplexer; and a plurality of signal light units connected to the optical multiplexer/demultiplexer, wherein each connected signal light unit transmits a signal light having a predetermined wavelength, the predetermined wavelengths of the signal lights transmitted by each of the signal light units are different from each other, the optical multiplexer/demultiplexer multiplexes together the transmitted signal lights, the optical multiplexer/demultiplexer receives an optical signal having a plurality of different wavelengths multiplexed together, the optical multiplexer/demultiplexer demultiplexes the received optical signal into the plurality of different wavelengths, the demultiplexed plurality of different wavelengths correspond, respectively, to the plurality of connected signal light units, the connected plurality of signal light units each receive the corresponding, demultiplexed different wavelength, a respective connected signal light unit is detachably connected to the optical multiplexer/demultiplexer and is thereby replaceable by a pumping light unit which connects to the optical multiplexer/demultiplexer in place of said respective connected signal light unit, the connected pumping light unit emits pumping light, the optical multiplexer/demultiplexer multiplexes the emitted pumping light together with the signal lights transmitted by the connected signal light units other than said respective connected signal light unit that has been replaced, the pumping light is at a predetermined wavelength which causes Raman amplification for at least one of the signal lights multiplexed together with the pumping light, and the optical multiplexer/demultiplexer is configured to receive both the wavelength of the signal light transmitted by said respective connected signal light unit and the wavelength of the emitted pumping light.