Recent progress on the quantum-dot avalanche photodiode (QDAP)

In this summery we report experimental results on the linear-mode operation of new QDAP structures. Two different detector structures, grown using solid source molecular beam epitaxy, were processed and characterized. In both structures, the n-i-n DWELL detector was grown on top of the p-i-n APD section in a single-step epitaxy. In the first structure, the multiplication region of the APD section consists of a 200-nm GaAs layer while the second device has a 200-nm AlGaAs-GaAs heterojunction multiplication region.