Abstract

A calculation of the noise characteristics of beveled-edge avalanche photodiode arrays is presented. It describes well the observed results from 64-element arrays with 1.27 x 1.27 mm2 and 0.45 x 0.45 mm2 pixel size. The main source of noise at low gain is Johnson noise from the interpixel resistance. At high gain, the shot noise from the bulk dark current dominates. There is an intermediate narrow gain region (M -10-25) where the noise current decreases to 0.1 pA/vHz in both arrays and the performance of the pixels is optimized. A comparison between the model and experimental data shows that the bulk dark current per unit area is higher in the array than a single element APD. This increase is most probably due to the grooving process, which create defects that generate high bulk dark current. © 1998 IEEE.