| 摘要 |
PURPOSE:To decrease the loss between a subscriber fiber and an optoelectric converter and between the said fiber and an electrooptic converter by using multiplexers/ demultiplexers connected in cascade and photocouplers in place of an photocoupler of 4-input and 1-output. CONSTITUTION:Only the light of wavelength lambda1 passes through between end faces 101 and 102 of a multiplexer/demultiplexer 100 and only the light of wavelength lambda2 passes through between end faces 103 and 102. Only the light of wavelength lambda1 passes through between end faces 105 and 106 of a multiplexer/demultiplexer 104 and only the light of wavelength lambda2 passes through between end faces 107 and 106. A transmission signal is switched by a switch 801 and inputted to either an electrooptic converter 802 or 803, the signal is converted into a optical signal of wavelength lambda1 by the converter 802 and the signal is converted into an optical signal of wavelength lambda2 by the converter 803 and they are led to the subscriber fiber 810 through multiplexers/ demultiplexers 100, 104 via a photocoupler 108 of 2-input/1-output. The optical signal sent to a terminal equipment through the subscriber fiber 810 is given to an optoelectric converter 805 or 808 depending on the wavelength of the signal via a photocoupler 108 and the multiplexer/demultiplexer 104 and one of the output electric signals is selected as a reception signal by a switch 804. |
