Wideband Polarizer in the Middle IR Wavelength Region Based on Guided Mode Resonance Effect

An extremely wideband polarizer operating in the middle IR wavelength region is designed and fabricated using the single layer silicon material on the magnesium fluoride substrate. The polarizer is fabricated by the self-developed blue light laser direct writing system and dry etching. The fabricated polarizer has high transmission (>95 %) for TM polarization light and low transmission (<;5 %) for TE polarization light over 330-nm wavelength range. The experiment extinction ratio is about 100:1 at the wavelength 3080 nm. The great polarizing property can be shown in a quietly broad IR wavelength band using this simple and compact structure.