AUTOMATIC POLARIZED WAVE CONTROLLER FOR OPTICAL COHERENT COMMUNICATION

摘要

PURPOSE:To miniaturize a device and extend the repeating interval by reducing an optical device part and increasing an electric circuit part and not using the power of a reception light for monitor of the polarization state. CONSTITUTION:The reception light is applied to a photoelectric transducer 21 through a half mirror 24, and the electric signal obtained there is subjected to heterodyne detection, and the output of an intermediate frequency amplifying filter 22 has the amplitude value detected by an amplitude detector 11, and the analog signal is converted to a digital signal by an A/D converter 12. The other output of the intermediate frequency amplifying filter 22 is sent to a reception data demodulator. The signal converted by the A/D converter 12 is processed in such direction on a basis of an algorithm in the mountaineering method by a microprocessor 13 that the amplitude value is maximum. Since optical signals only for control are not used at all, the intensity of the reception light is not lost and the repeating interval is extended.