Edge-coupled Sub-micron InP-based Double-Hetrostructure Phototransistors with optical-gain cutoff frequency of 184 GHz

We present a high speed phototransistor with integrated waveguide based on our InP double hetrojunction bipolar transistor (DHBT) process technology. By using only the base as an absorption layer, the slow drifting holes in the collector layer are avoided. We measured an optical-gain cutoff frequency of 184 GHz at a base current of Ib=1500 ìA using devices with emitter dimensions of A=0.7 x 8 ìm2.