InGaAs/InAlAs SAGCMCT avalanche photodiode with high linearity and wide dynamic range

Linearity is a very important parameter to measure the performance of avalanche photodiodes (APDs) under high input optical power. In this paper, influence absorption layer on linearity APDs carefully studied by using bandgap engineering with structure model separated absorption, grading, charge, multiplication, and transit (SAGCMCT). The simulated results show that in hybrid device 1 dB compression point can be improved from -9 dBm -2.1 increasing proportion p-type layer. only one layer, doping level also improve -8.6 1.43 at gain 10. Therefore, critical for APDs.