| 摘要 |
PURPOSE:To compensate the deterioration in BER due to returned light noise by reflection by controlling a bias current. CONSTITUTION:When BER is deteriorated due to returned light noise by reflection a bias current control signal based on deterioration information is sent from a terminal station. The bias current control signal is received by a control signal reception circuit 5 and a bias current of a single longitudinal mode semiconductor laser diode (DFB-LD) 4 is controlled by a bias current control circuit 6 to improve relative intensity noise(RIN), thereby wading the deterioration in the error rate. |
