Monte Carlo simulation of excess noise in heterojunction avalanche photodetector

A Monte Carlo (MC) simulation of excess noise in heterojunction avalanche photodetector (APD), made up of InP/InGaAs, is made. The simulation is based on the hard threshold dead space consideration in the displaced exponential model of the distribution of ionization path lengths. Impact ionization and multiplication of electrons as function of ionizing electric field are also studied. The multiplication and noise are seen to be reduced compared to those in component materials. The simulated results are seen to agree well with the reports of other theoretical predictions and experimental results published in literatures.