Silicon as a photonic medium has unique advantages in telecommunication systems. It is transparent in the range of optical telecommunications wavelength (1.3 and 1.55 um) and has a high index of refraction. In addition, mature Si integrated circuit CMOS technology enables the implementation of dense silicon-based OEICs. The development of SiGe photodetectors, and especially the fist demonstration of high performance SiGe Avalanche photodiode(APD)(1), has drawn more attention to high speed SiGe APDs development for low cost optical communication.
