an apparatus for protecting an optical receiver from high power optical signals is disclosed . the apparatus generally includes an optical receiver and a semiconductor optical device configured to receive optical signals and transmit the signals to the optical receiver and operable to decrease amplitude of an input signal received at the device above a predetermined power level range . the apparatus further includes a controller operable to increase attenuation of the semiconductor optical device such that the signal transmitted to the optical receiver from the semiconductor optical device is at an optimum power level for the optical receiver .