| 摘要 |
PURPOSE:To provide a polarization dispersion compensating method which suppress the degradation in waveform due to polarization dispersion of a transmission line in an optical communication system. CONSTITUTION:Signal light 2 subjected to optical frequency modulation to a frequency f0 is made incident on an optical fiber 8. In the exit end of the optical fiber 8, signallight 2 is separated into two orthogonal polarized waves by a polarized wave separating element 13 after passing a polarization control element 9 and a polarization maintaining fiber 10. Separated polarized signal light 2 is received by a balanced light receiver and is converted into an electric signal, and an intensity signal 18 of the component of the frequency f0 out of this signal is detected. The polarization control element 9 is so controlled that this intensity signal 18 is always minimum. Polarization dispersion of the optical fiber and that of the polarization maintaining fiber 10 are cancelled by each other by this polarization control, and the degradation in waveform due to polarization dispersion is suppressed. |
