SYSTEM FOR COMPENSATING OPTICAL BRANCHING LOSS

摘要

PURPOSE:To allow the packaging at a higher density and the reduction of a size and cost and to compensate a light loss by connecting a rare earth element-added optical fiber amplifier for amplifying the exit/incident light in a port according to the intensity of incident exciting light to one port side. CONSTITUTION:The signal light transmitted from a light transmitter/receiver 1 of a central telephone exchange TEX arrives at a bright line point FDP while being subjected to an attenuation effect in an optical fiber 4. On the other hand, the exciting light emitted from a light source 6 passes the optical fiber 7 and arrives at the bright line point FDP. This light is multiplexed with the signal light in an optical multiplexer/demultiplexer 8. The multiplex light is made incident to the optical fiber amplifier 9 where the signal light is amplified by a prescribed gain. The amplified signal light is made incident through the filter 10 to one port on the central telephone exchange TEX side of an optical star coupler 2 where the light is branched by N. The branched light rays are propagated in the respective optical fibers 5-1 to 5-N and are received in respective light transmitter/receivers 3-1 to 3-N on a subscriber SUB side. The exciting light is shut off in the filter 10 and is thereby prevented from arriving at the optical star coupler 2.