| 摘要 |
PURPOSE:To expand a dynamic range by selecting the output of a photodetector when a light receiving level by a semiconductor laser is higher than a prescribed value. CONSTITUTION:The photodetector 14 arranged at a light transceiver on one side neighboring to an end face at a side opposite to respective transmission terminal of the semiconductor laser 13, and a control circuit 11 including a means which selects the output of the photodetector 14 when the light receiving level by the semiconductor laser 13 is higher than the prescribed value are provided. Also, a photodetector 34 and a control circuit 31 are provided similarly at a light transceiver on the other side. Light attenuated by transmitting the semiconductor laser 13 can be received when a reception level is too high in direct reception. |
