OPTICAL TRANSMITTER/RECEIVER

摘要

An optical transmitter/receiver having a high-speed main transmission channel and a low-speed transmission channel usable for control. The optical transmitter/receiver includes a transmitting unit for generating an optical signal by superposing a main transmission channel signal in a wide band coded by an encoding method involving redundancy on a sub-transmission channel signal in a narrow band having a power spectrum in a power spectrum blank region of the main transmission channel signal. The signal intensity of the main transmission channel signal is greater than that of the sub-transmission channel signal. Therefore cross modulation due to the grain adjusting mechanism of limiter type can be reduced. The reception condition of the main transmission channel can be made almost equivalent to that of the sub-transmission channel.