OPTICAL TRANSMITTER-RECEIVER

PURPOSE:To decrease a pulse width distortion by outputting a prescribed code depending on the polarity of a pulse width distortion resulting from the measurement of the pulse width distortion of an optical pulse signal. CONSTITUTION:A pulse width measurement circuit 18 measures a pulse width duty of a pulse voltage signal reproduced from a light from a transmission section at a reception section and when the duty is negative (45% or below) or positive (55% or over), a prescribed code is returned respectively to an opposite station. The returned code is received by a reception section of its own station and an on-timing control circuit 8 controls the pulse width of the optical signal according to the code and the transmission and reception are repeated again and when the pulse width duty stays within 45-55%, the code output is stopped. A regular pulse voltage whose pulse width duty is 45-55% is outputted from the reception section through the operation.