Single-layer structure supporting both heterojunction bipolar transistor and surface-normal modulator

The authors have produced a n-p-i (shallow quantum well)-n GaAs-AlGaAs layer structure from which either heterojunction bipolar transistors (HBTs) or surface-normal modulators may be fabricated, allowing single-growth integration of those devices for optical interconnects. The shallow quantum well region provides large electroabsorption while having no impedance to electron transport. The HBTs have a gain of 15. The modulators have a change in transmission from 30.7% to 50.1% for a change in bias from +1 V to -3V.>