Initial observations of optical injection locking of oscillators using heterojunction bipolar transistors.

For the first time, optical phase control of a hybrid heterojunction bipolar transistor (HBT) oscillator has been achieved. The results strongly indicate that the HBT is a suitable device for optically controlled oscillators. At a frequency of oscillation of 500 MHz a locking range of more than 15 MHz was measured (Delta f/f = 3 percent). The optical tuning range of the oscillator exceed 25 MHz.