Design of polarization insensitive Ge-on-Si waveguide-coupled photodetector by adjusting waveguide width

Abstract

Polarization dependency for waveguide coupled photodetector is investigated in terms of absorption efficiency and effective indices of quasi-TE/TM fundamental polarization modes with the waveguide width. Simulations are performed at the wavelength range from 1270 to 1360 nm and executed by using finite difference time domain (FDTD) method. Optimum polarization insensitive waveguide geometry is proposed.