Optoelectronic generation and modulation of millimeter waves in a single InP-GaInAs photo heterojunction bipolar transistor

We demonstrate the use of an InP-GaInAs photo heterojunction bipolar transistor as a millimeter wave transducer. A 45-GHz carrier signal is generated by mixing two optical signals impinging on the optical port at the base. Simultaneously, the base electrode is fed by an electrical signal which modulates the 45 GHz carrier. Analog modulation capabilities were characterized in terms of the modulation depth and linearity while digital modulation was evaluated by a measurement of bit error rates.