Effect of the ionization rate ratio on nonlinear distortion in avalanche photodiodes

The effect of the ionization rate ratio on the nonlinear distortion of avalanche photodiodes (APD's) was studied theoretically and experimentally. In the case of pure electron injection into the multiplication layer, the distortion decreases when the electron ionization rate become much larger than that of hole. The calculation is consistent with the experimentally measured distortion of superlattice and Ge avalanche photodiodes.