Broad visible spectral subwavelength polarizer with high extinction ratio using hyperbolic metamaterial

A subwavelength polarizer with an extinction ratio greater than 50 dB in the visible region (exceeding 80 dB in the 500 to 800 nm wavelength region) is presented that uses hyperbolic metamaterial decorated on each side with a subwavelength grating. The approach is based on the spatial frequency filtering characteristics of the hyperbolic metamaterial with its alternating metal-dielectric nano-film, which enables squeezing of bulk plasmon polaritons to support transverse magnetic polarized light transmission in the high spatial wavevector modes while suppressing other polarization mode waves over the broad visible spectrum. The proposed method exhibits a more realizable fabrication process than that used for a subwavelength polarizer based on high-aspect-ratio grating for broad spectrum and high-extinction-ratio performance. The subwavelength polarizer in this work is potential for the high-sensitivity polarimetric imaging.