Infrared micropolarizer array fabricated using a reversal nanoimprint

Using a reversal nanoimprint and metal evaporation process, we fabricated a micropolarizer array for the 2.5-7 mu m wavelength region. The micropolarizer array has a unique unit, which is composed of 2 x 3 arrays on an intrinsic silicon substrate. Each array consists of a 200 nm period bilayer Al grating in a 1.3 mm x 1.3 mm aperture. The transmittance of transverse magnetic polarization of each array is greater than 65% in the 2.5-7 mu m wavelength range, and the extinction ratio is over 35 dB in the 3-4 mu m and 6-7 mu m wavelength range. This fabricated micropolarizer array has lower costs and better compatibility with microfabrication processes. (C) 2018 Optical Society of America