| 摘要 |
PURPOSE:To reduce transmission output, to improve safety and to facilitate the adjustment of an optical axis by arranging optical beams for position detection around an optical communication beam. CONSTITUTION:A transmission signal 100 is modulated and supplied to a semiconductor laser 5. The optical communication beam 102 being the output of the laser 5 is radiated to the external space of a transmitter 1a. On the other hand, the output of a light source control circuit 3 is connected to light sources 6 and 7, and the beams for position detection 103a and 103b being the outputs are radiated to the external space of the transmitter 1a so that they are arranged in parallel with the beam 102 at the circumference of the beam 102. In a receiver 2a, the beam 102 or the beams 103a and 103b are made incident on a photodetector 10, and the output is connected to a modulation circuit 11 and a position detection circuit 12. The output of the circuit 11 is outputted as a reception signal 101. The output of the circuit 12 is connected to a position control circuit 13 and the output of the circuit 13 is supplied to a stage 14 changing the position of the receiver 2a. |
