摘要 |
<p>An optical receiver according to the present invention is used for detecting FSK or PSK signal light directly. The receiver has a PM fiber and a peak detector. The peak detector detects an amplitude of a demodulated output signal. In accordance with an output signal of the peak detector, a polarization condition of a signal light to be supplied to the PM fiber is controlled so as to keep the output of the peak detector maximum. <IMAGE></p> |