| 摘要 |
PURPOSE:To provide an optical ping-pong transmitter in which the effect of a reflected light is avoided without extending a guard time. CONSTITUTION:Upon the reception of a reflected light for a reception period of transmitters 2-10, 2-11, the gain of an AGC amplifier circuit 1-2 is adjusted corresponding to an amplitude level of a reflected light to be a low gain. When the reflected light is lost in this state, an output of an identification circuit 1-4 goes to zero, and when a forced reset circuit 2-1 detects it that the zero state is consecutive for a specific period, the AGC amplifier circuit 2-1 is forcibly reset. Thus, the gain of the AGC amplifier circuit 2-1 is restored to a maximum gain, and normal reception of a substantial reception signal is attained even when the reception signal is attenuated. |
