Deep silicon grating as high-extinction-ratio polarizing beam splitter

摘要

A deep binary silicon grating as high-extinction-ratio reflective polarizing beam splitter (PBS) at thewavelength of 1550 nm is presented.The design is based on the phenomenon of total internal reflection(TIR) by using the rigorous coupled wave analysis (RCWA).The extinction ratio of the rectangular PBSgrating can reach 2.5x10^5 with the optimum grating period of 397 nm and groove depth of 1.092 μm.The efficiencies of TM-polarized wave in the 0th order and TE-polarized wave in the -1st order can bothreach unity at the Littrow angle.Holographic recording technology and inductively coupled plasma (ICP)etching could be used to fabricate the silicon PBS grating.