GeSn-on-insulator dual-waveband resonant-cavity-enhanced photodetectors at the 2 µm and 1.55 µm optical communication bands

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