APPARATUS FOR COMPENSATION OF DISTORTION OF POLARIZATION DEPENDENCE IN OPTICAL COMMUNICATION

摘要

PURPOSE: To minimize distortion by utilizing technique for turning optical signals transmitted through an optical fiber into output polarizing state having minimum received signal distortion, or receiving only the output polarizing state having minimum signal distortion. CONSTITUTION: In order to transmit the optical signal from a station 12 through an optical fiber 14 to a station 16, a laser transmitter 10 is connected and the optical signal from the optical fiber 14 is detected by a photoelectric detector 18 and converted into an electric signal. The signal from the detector 18 is turned toward a threshold detector 24 after a noise is coupled by a code 22. The signal from the detector 24 has a high error rate in comparison with the signal from the detector 20 because of the additional noise. These two signals are guided to an exclusive OR gate 26 and compared with the signal of high error rate from the detector 24, and the signal outputted from the gate 26 is guided to a counter 28 and sent to a control circuit 30 for performing a gradient search after its bit error rate(BER) is determined.