Polarization beam splitters based on 2D supercell gratings at normal incidence

A 2D supercell grating was proposed to work as a polarization beam splitter (PBS) at normal incidence, which directed TE-polarized light to (0, ±1) order and TM-polarized light to (±1, 0) order. The diffraction efficiency of targeted transmitting orders reached 71.32% and the extinction ratio exceeded 19.97 dB for TE- or TM- polarized illumination with 1550nm wavelength. Meanwhile, the (0, 0) order was well suppressed. The proposed 2D supercell grating is suitable for compact polarization systems.