| 摘要 |
PURPOSE:To vary a transmission capacitance by constituting the input and output circuits of a recovery relay circuit by at least on optical switch and controlling the optical switch so as to switch the transmission direction. CONSTITUTION:The input and output of a light reception/transmission circuit 9 connect to 1X2 optical switches 5, 6 respectively via demultiplexers 1, 2. The optical switch 5 is connected to a transmission line 12 at the side A and the optical switch 6 is connected to a transmission line 13 at the side B. The optical switches 5, 6, 7, 8 are switched normally to the position of contact (a). In this state, the circuit 9 sends an light signal from the side A to the side B and a light reception/transmission circuit 10 sends the light signal from the side B to the side A. In switching the optical switches 5, 6 to the position of contact (b), the circuit 9 sends the light signal in the opposite direction (from side B to side A). In switching the optical switches 7, 8 to the position of contact (b), the circuit 10 sends the light signal in the opposite direction (from side A to side B). |
