Transparent emitter contact HBT's for direct optical injection locking of oscillators

Direct optical injection locking and tuning of high frequency oscillators made with GaAs-AlGaAs heterojunction bipolar transistors (HBT's) have been investigated. A new HBT technology using transparent indium-tin-oxide (ITO) emitter contacts for convenient optical access has been developed. Optical injection locking and tuning experiments have been performed on 6 GHz HBT oscillators. A locking range up to 2.5 MHz, and a tuning range up to 25 MHz have been measured with the injection of optical RF power at 30 dB below the oscillator power level.<<ETX>>