Investigation of the SiGe Waveguide Photodiodes Using FDTD Method for High Speed Optical Communication

Introduction

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.

In this paper, we present two high performance SiGe Waveguide PhotoDiodes[2], for high-speed applications. Both the waveguides and the photodiodes were simulated self-consistently using the vector helmholtz equation for mode calculation and Finite Difference Time Domain FDTD for light propagation analysis.