Low-index cladded wire grating as broadband polarizing beam splitter

摘要

A sandwich structure including subwavelength grating and low-index thin film as a broadband polarizing beam splitter(BPBS) is demonstrated. The BPBS is studied by using the rigorous coupled-wave analysis (RCWA) numerical scheme.The low-index thin-film with optimum thickness forms between the silicon substrate and the subwavelength grating.While the thickness of low-index thin film is larger than 0.6 ?m, the reflectivity of TE wave is larger than 0.95 in thewavelength region [1.29 ?m, 1.66 ?m] under the normal incidence. In this region, the reflectivity of TM wave is low.Meanwhile, it is also found that while the thickness of low-index thin film rise to 0.9 ?m, the extinction ratio of TMpolarization is less than 0.047 in the wavelength region [1.35 ?m, 1.48 ?m]. Therefore, the designed sandwich structureconsisted of subwavelength grating, low-index thin film and silicon substrate can be used as broadband polarizing beamsplitter.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.