| 摘要 |
PURPOSE:To reduce the deterioration in the reception sensitivity caused by the reflection of light in an optical connector section by providing a subtraction circuit to the output side of a optical receiver, receiving a drive signal driving an optical transmitter, adjusting the phase and amplitude of the drive signal and giving the result to the subtraction circuit. CONSTITUTION:The optical transmitter 6 is driven by a drive circuit 7 and sends and optical signal, and the optical signal is sent to an optical fiber 7 through an optical multiplexer/demultiplexer 3. The optical fiber transmission line 7 and the optical multiplexer/demultiplexer 3 are connected by an optical connector 2 and then part of the optical signal reflected in the optical connector 2 is returned to the optical multiplexer/demultiplexer 3 and given to the subtractor 4 through the optical receiver 5. On the other hand, the output of the drive circuit 7 is branched and given to the subtractor 4 through a delay adjustment circuit Delay 8 and an amplitude adjusting circuit 9. That is, the output of the drive circuit 7 is adjusted for a prescribed time by the delay adjusting circuit 8, the amplitude is adjusted by the amplitude adjusting circuit 9 and given to the subtractor 4. Thus, a reflected wave is cancelled and the effect of the reflecting wave is reduced without giving effect onto the amplitude of the optical signal inputted from the transmission line 1. |
