Patent ID: 6943630

Claim:
An amplifier circuit for receiving an optical signal, which amplifier circuit comprises: a light sensitive member arranged to receive an optical input signal and to deliver an electric signal in response to the received optical signal, an amplifier unit with a first input arranged to receive the electric signal from the light sensitive member, wherein the amplifier unit is arranged to influence the amplification of the electric signal and to deliver an amplified output signal via a first output, wherein the amplifier unit does not have any further input specially intended for controlling the amplification of the amplifier unit, characterised by a filter unit arranged to prevent a possible direct current in the electric signal from the light sensitive member from reaching said first input, wherein said light sensitive member is arranged such that a possible direct current from the light sensitive member would be directed into said amplifier unit via the first input if said filter unit were not arranged to prevent such a direct current, an a control unit connected to said first input and arranged to control the power of an electric current in a direction in via the first input for thereby influencing the power of said output signal.