High-gain and very sensitive photonic switching device by integration of heterojunction phototransistor and laser diode

摘要

A photonic switching device with very large gain and high sensitivity has been developed by the vertical and direct integration of a heterojunction phototransistor and a laser diode. The device switches on with very low input power of approximately 10 nW and emits output power of approximately 4 mW under continuous-wave conditions at room temperature. The minimum energy for switching on is estimated to be as low as 80 fJ. The internal optical feedback of the device is quantitatively discussed to interpret the low-power operation for the switch-on.