Patent ID: 7326921

Claim:
An optical receiver for receiving an optical signal and outputting an electrical signal corresponding to said optical signal, said optical receiver comprising: an avalanche photodiode for converting said optical signal into a photocurrent corresponding to said optical signal depending on a bias voltage applied to said avalanche photodiode at a temperature; an adjusting circuit for outputting said bias voltage by adjusting a DC voltage input to said adjusting circuit in accordance with a control signal; and a controller for outputting said control signal to said adjusting circuit in accordance with said photocurrent and said temperature of said avalanche photodiode, wherein said adjusting circuit includes a resistor and a variable current source, said resistor being connected in serial to said avalanche photodiode, said variable current source being connected in serial to said resistor and in parallel to said avalanche photodiode, and wherein said variable current source outputs a control current in accordance with said control signal output from said controller, said bias voltage being lowered by a product of the resistance of said resistor and said control current from said DC voltage applied to said adjusting circuit.