Optical amplifier device and bidirectional wavelength division multiplexing optical communication system using the same

In a bi-directional wavelength division multiplexing optical communication system of the type having first and second optical transmitter/receiver units for transmitting and receiving wavelength-division-multiplexed optical signals, respectively, and an optical fiber serving as a transmission medium for a forward optical signal traveling from the first optical transmitter/receiver unit to the second optical transmitter/receiver unit and a reverse optical signal traveling from the second optical transmitter/receiver unit to the first optical transmitter/receiver unit, each of the forward and reverse optical signals being composed of a plurality of channels with different wavelengths, and an optical amplifier device for amplifying the forward and reverse optical signals, comprising:

• a first interleaver for interleaving the channels of the forward optical signal received at a first terminal thereof and the channels of the reverse optical signal received at a second terminal thereof, in accordance with the wavelengths of the channels, and outputting an interleaved optical signal at a third terminal thereof;
• an optical fiber amplifier unit comprising a single amplifier for amplifying only the interleaved optical signal received from the third terminal of the first interleaver and outputting the amplified optical signal;
• and,
• a second interleaver for splitting the amplified optical signal, received at a third terminal thereof, into the forward and reverse optical signals in accordance with wavelengths and outputting the forward and reverse optical signals at first and second terminals thereof, respectively.