| 摘要 |
PROBLEM TO BE SOLVED: To suppress an unsteady state of output by converting an optical signal into an electric signal, deciding whether an information signal is included in the electric signal and controlling the decision result output included in a prescribed frame. SOLUTION: A received burst optical signal is converted into an electric signal by a photodiode 1 and then converted into a voltage signal by a preamplifier 2. Then the differential signals S+3 and S-3 are outputted via an amplifier 3 having two output terminals of phases opposite to each other. An identification circuit 4 compares the potentials of inputted signals S+3 and S-3 and holds the potential difference peaks of these signals. A reset signals SRS is externally inputted to a peak holding element to initialize this element, and the identification level is controlled in each burst cycle. An output unsteady state is inhibited by the circuit 4, an inhibition circuit 5 and a control circuit 10 before the signal SRS is inputted and then the tip of a burst signal is detected. |
