GeSn-on-insulator dual-waveband resonant-cavity-enhanced photodetectors at the 2 μm and 155 μm optical communication bands

Abstract

Germanium-tin-on-insulator (GSOI) has emerged as a new platform for three-dimensional (3D) photonicintegrated circuits (PICs). We report the first demonstration of GeSn dual-waveband resonant-cavity-enhanced photodetectors (RCE PDs) on GSOI platforms with resonance-enhanced responsivity at both the 2 μm and 1.55 μm bands. 10% Sn is introduced to the GeSn absorbing layer to extend the detection wavelength to the 2 μm band. A vertical Fabry–Pérot cavity is designed to enhance the responsivity. The measured responsivity spectra show resonance peaks which cover a wide wavelength range near both the 2 μm and conventional telecommunication bands. This work demonstrates that the GeSn dual-waveband RCE PDs on a GSOI platform are promising for CMOS-compatible 3D PICs for optoelectronic applications in 2 μm and telecommunication bands.