Patent ID: 6941074

Claim:
A bi-directional optical wavelength division multiplexed transmission system for transmitting an upstream optical signal and a downstream optical signal along a same path within a same transmission line, said bi-directional optical wavelength multiplexed transmission system comprising: a first transmitting unit setting the upstream optical signal to a first band and transmitting the upstream optical signal set to the first band; a second transmitting unit setting the downstream optical signal to a second band which is different from the first band and transmitting the downstream optical signal set to the second band; and a distributed amplifier unit having a first pumping light source for pumping only the upstream optical signal set to the first band, and a second pumping light source for pumping only the downstream optical signal set to the second band, wherein said first pumping light source amplifies the upstream optical signal set to the first band through backward pumping, and said second pumping light source amplifies the downstream optical signal set to the second band through backward pumping along the same path within the same transmission line.