Patent ID: 6057951
Filing Date: 2000-05-02
Classification: H01S,H04B

Abstract:
An optical receiver circuit comprising:an optical amplifer for amplifying an optical input signal;photoelectric converting means for converting an optical signal output from said optical amplifier to an electrical signal;first gain control means for detecting a level of the electrical signal output from said photoelectric converting means to control the gain of said optical amplifier such that the detected level of the electrical signal is set to a predetermined level;optical input signal loss detecting means for detecting said input signal loss of said optical input signal; andsecond gain control means for controlling the gain of said optical amplifier to be lower the a maximum gain when said optical input signal loss detecting means detects the input signal loss;wherein said first gain control means comprises peak level detecting means for detecting a peak level from the electrical signal output from said photoelectric converting means, and said first gain control means controls the gain of said optical amplifier such that the peak level detected by said peak level detecting means is set to a predetermined level.