Design and characterization of Ge passive waveguide components on Ge-on-insulator for mid-infrared photonics

We successfully demonstrate Ge passive components including grating couplers, MMI couplers, and micro-ring resonators on GeOI at 2-μm wavelength. We also reveal the thermo-optic coefficient in Ge strip waveguide is 6×10
^-4
/°C, greater than in Si.