We introduce a calculation method for the frequency response of an avalanche photodiode (APD) considering the electric field profile. By applying this method to an InGaAs APD, we obtained the relationship between the gain- bandwidth (GB) product and the carrier concentration (Nb) of the multiplication layer. This result explains the present experimental data and shows that the upper limit of the GB product is 140 GHz at Nb = 2 × 1017 cm−3. This limit is determined by the onset of the tunneling current in the multiplication layer.
© 1988 Optical Society of AmericaPDF Article