Electro-optical mixing in an edge-coupled GaInAs/InPheterojunction phototransistor

Abstract

Gain nonlinearities at low optical power of an edge coupled GaInAs/InP heterojunction bipolar phototransistor are used to mix the optical demodulation products of two (or more) laser beams. One beam could be CW or low frequency range modulated, since the other one is RF or microwave modulated. Experiments carried out for 2 GHz and 2 kHz, respectively, show the mixing of the two demodulated electrical signals in the phototransistor.