Design of rectangular-groove fused-silica gratings as polarizing beam splitters

Abstract

Abstract:The application of rectangular-groove fused-silica gratings as polarizing beam splitters (PBSs) under Littrow incidence is investigated. Based on the simple modal method, two different cases of PBS gratings are designed. The achieved solutions, which are independent on the incident wavelength, are verified by the rigorous coupled-wave analysis and expressed in several polynomials instead of listing one or two numerical solutions. More importantly, on the basis of the designed PBS gratings, a porous fused silica antireflective film is introduced to improve their performances. Theoretical results indicate that such modified rectangulargroove PBS gratings exhibit higher diffraction efficiencies (over 0.99) and larger spectral bandwidths.

Polarization-Independent Two-Layer Grating With Five-Port Splitting Output Under Normal Incidence

“…In most reported traditional works, design of numerous polarization-independent beam splitter gratings are excessively relied on numbers of different output diffraction orders. Generally, under Bragg incidence, it is very easy to design polarization-independent grating splitters (i.e., high-efficiency gratings [6]- [8], twoport gratings [9]- [11], polarization-selective gratings [12]- [14], polarizing beam splitter gratings [15]- [19]), because of the numbers of different output diffraction orders are no more than two for transverse-electric (TE) polarization or transverse-magnetic (TM) polarization. Under second Bragg incidence, It is relatively easy to obtain optimized polarization-independent high-efficiency grating [20] or two-port beam splitter grating [21].…”