OPTICAL TRANSMISSION LINE

摘要

PURPOSE:To ensure the communication among nodes by using an optical amplifier provided to an optical tap so as to amplify optical signals from each optical tap thereby making output levels of the signals equal to each other. CONSTITUTION:When an electric signal is sent from a computer 42 of a transmission node 4 to an E/0 converter 40 through an electric signal transmission line 41, the electric signal is electrooptic-converted and the result is inputted to an optical tap 2 through an optical fiber 45, an optical demultiplexer multiplexer 46 and an optical drop cable 3. An optical signal entering a trunk line optical fiber 1 is branched into two at a 1st optical demultiplexer multiplexer 20 of an adjacent optical tap 2. The optical signal entering an optical amplifier 5 is amplified therein, in which a transmission loss or the like by the 1st optical demultiplexer multiplexer 20 in the optical tap 2 and the trunk line optical fiber 1 is compensated, and the level is kept the same as the level having been inputted from the optical tap and the signal is outputted to the trunk line optical fiber 1.