| 摘要 |
PURPOSE:To detect deterioration in the spectrum of a light source by varying a timing phase for identification by a control signal from the outside. CONSTITUTION:A reception waveform 3 can be obtained by applying equalizing amplification on an optical signal received at an optical receiver 1 at an equalizing amplifier circuit 2. An identification circuit 4 identifies and reproduces a signal by a timing signal from a timing circuit 7 superposed on the reception waveform 3, and inputs the output to a light source driving circuit 5, and the light source driving circuit 5 makes a light source 6 emit light by driving. A supervisory control circuit 9 supervises the output of the identification circuit 4, and sends a control signal to a phase control circuit 8, and the phase control circuit 8 varies the timing phase for identification of the timing circuit 7 corresponding to the control signal, and the identification circuit 4 measures the digital error rate of each identification phase. When the digital error rate coincides with broken line shown in figure, it is judged as the deterioration in the spectrum of the light source 6. In such a way, an optical repeater having a function to observe the deterioration in the spectrum of the light source can be obtained. |
