Abstract: An optical receiver having enhanced dynamic range is achieved through the use of a variable impedance shunt 203 disposed at the receiver input. The optical receiver comprises an optical detector 102 serially connected to a transimpedance amplifier 201. The optical detector 102 receives an optical signal having a variable optical power level and modulation bandwidth and generates a corresponding electrical current therefrom. The transimpedance amplifier provides a fixed amount of gain and converts the electrical current to an output voltage. An automatic gain control circuit 202 produces a control signal which varies in response to the amplitude of the output voltage. The control signal is applied to the variable impedance device to vary the impedance therein. This maintains the output voltage at a predetermined amplitude over the modulation bandwidth without any significant reduction in receiver sensitivity.