OPTICAL SURGE SUPPRESSION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To improve the reliability of an optical transmission system by compensating reduction in a level of a signal light and surely suppressing production of optical surge. SOLUTION: The circuit consists of an optical surge compression circuit 102 to compress an optical surge included in an input signal light outputted from an input side optical amplifier 10 and of an optical output level compensation circuit 103 that superimposes a pseudo signal on the input signal light for a period when the reduction in the level of the input signal light is caused in the case that a steep level reduction such as momentary interruption takes place in the input signal light so as to compensate apparently the reduction in the level of the input signal light. Thus, the production of optical surge is prevented and steep level reduction of the input signal light is compensated.