Low frequency noise in separate absorption, grading, charge and multiplication (SAGCM) avalanche photodiodes

Low frequency noise spectra of five SAGCM APDs were measured. The experimental noise current spectra were fitted with S/sub I/=A/sub F/I/sub d//sup x//f/sup y/+2qI/sub d/M/sub eff/. Any enhancement in shot noise was included in M/sub eff/. The A/sub F/ factors were found to vary from 10/sup -7/ to 10/sup -5/ and were related to the I-V characteristics of these APDs.