Responsivity and noise characterisation of ge avalanche photodiode throughout wavelength range 1.1–1.7 μm

Mixed carrier injection in a commercial n+-p germaniun a.p.d. causes the excess multiplication noise to be wavelength dependent, with averaged k-values of around unity. The quantum efficiency is 70% between 1.1 and 1.5 μm, and the unmultiplied bulk leakage current density is estimated to be 3.5×10-4 A cm-2