| 摘要 |
PURPOSE:To provide a light receiver controlled so that the optimum state of the receiver for input light in which a quenching ratio is deteriorated can be obtained in an optical communication system. CONSTITUTION:Incident light Pin in which the quenching ratio is deteriorated is inputted to an optical detector 1, and the output of the optical detector 1 is inputted to a transimpedance type preamplifier 2. A mean value detector 3 and a peak value detector 4 are connected to the output of the preamplifier 2. The output of the mean value detector 3 and that of the peak value detector 4 are inputted to an offset value detector 5, thereby, output in accordance with the offset value of an input electrical signal to the preamplifier 2 can be obtained as the output of the offset value detector 5. Meanwhile, a constant current circuit 6 consisting of a resistor 10 and transistors 11, 12 is connected in series to the optical detector 1. Offset in the input electrical signal to the preamplifier 2 can be eliminated by controlling a current value on the constant current circuit 6 by the output of the offset value detector 5, thereby, a satisfactory receiving state can be obtained. |
