Patent ID: 8358938

Claim:
An optical receiver, comprising: an optical receiver module including, a photodiode for detecting an input optical signal and converting said input optical signal to a photocurrent by being supplied with a bias voltage, a pre-amplifier for converting said photocurrent to a differential voltage signal, a level monitor for monitoring an average of said input optical signal, said bias voltage being supplied to said photodiode through said level monitor, and a squelching unit for fixing an output of said optical receiver module at a preset voltage when said average of said input optical signal monitored by said level monitor is less than a reference level; and a main amplifier coupled with said optical receiver module in an AC mode, wherein said squelching unit includes a differential circuit, a source transistor operating as a current source of said differential circuit, and a bypassing transistor for bypassing an output of said differential circuit, and wherein said source transistor is turned off and said bypassing transistor is turned on when said average of said input optical signal is less than said reference level.