Monolithic Germanium PIN Waveguide Photodetector Operating at 2 µm Wavelengths

We demonstrated Ge PIN waveguide photodetector operating at 2 μm wavelengths monolithically integrated on Ge-on-insulator platform. Despite at sub-bandgap wavelength, 500μm-long photodetector exhibited 0.25 A/W responsivity at -5 V, attributable to the defect-mediated detection mechanism.