Silicon Waveguide-Based Polarization Rotator

Silicon-based photonic circuit is very promising as a platform for highspeed communication due to its compatibility in the conventional CMOS process as well as the ability to integrate electronic and optical components on the same silicon chip. However, due to the high structural birefringence of silicon waveguides, which may cause unfavorable polarization-dependent performance, polarization transparent circuit is always preferred. A silicon waveguide-based polarization rotator is then a key device for polarization diversity circuit. In this chapter, we present two fabrication methods to obtain silicon waveguide-based polarization rotator. The performance of the polarization rotator is evaluated through finite-difference-time-domain simulations and also experiments. The experimental results show that an efficient 12.4 dB extinction ratio is achieved through a polarization rotator.