Patent ID: 7050724

Claim:
A method for controlling an optical receiver, the method comprising the steps of: providing an optical receiver including a transimpedance amplifier providing the output of the optical receiver; a photo detector for converting optical power arriving at the receiver into electric current, output of the photo detector being operationally connected to the input of the transimpedance amplifier; and a control loop consisting of the transimpedance amplifier, a PIN diode having a first terminal operationally connected to the input of the transimpedance amplifier, and means for controlling current passing through the PIN diode by adjusting an impedance of the PIN diode; the PIN diode and the means for controlling the current passing through the PIN diode being connected in series between the input and the output of the transimpedance amplifier; controlling current passing through the PIN diode by adjusting an impedance of the PIN diode wherein the PIN diode is used as the adjustable impedance element, and a direct voltage component is separated from a voltage on the output of the transimpedance amplifier; and adjusting a voltage over the PIN diode on a basis of a direct voltage component of the voltage on the output of the transimpedance amplifier by means for controlling and adjusting voltage connected in series with the PIN diode between the input of the transimpedance amplifier and the output of the transimpedance amplifiers, whereby properties of the PIN diode cause the transimpedance amplifier to serve as a direct voltage amplifier and stabilize the direct current operation point of the transimpedance amplifier when the optical power arriving at the photo detector is above a given threshold.