Total internal reflection fused-silica grating for splitting polarized femtosecond beams

We described a PBS grating based on total internal reflection (TIR) to realize high efficiency. The grating period and depth are optimized using rigorous coupled wave analysis (RCWA) for a femtosecond laser wavelength of 800 nm. Efficiencies can reach unity for both TE-polarized wave in the 0th order and TM-polarized wave in the -1st order. Based on TIR, all the incident energy can be reflected without transmission regardless of grating tooth shape. The presented TIR PBS can stand with high laser power systems without absorptions of metal or complicated structures of multilayer coatings.