A low-cost mid-infrared polarizer with double-sided silica anti-reflection films fabricated using nanoimprint

To make a low-cost and effective infrared polarizer, we designed a mid-infrared polarizer with double-sided silica anti-reflection films. Double-sided silica was oxidized on a silicon substrate. Then, micro gratings were fabricated on silica by using soft nanoimprint lithography and metal thermal evaporation process. The transverse magnetic wave (TM) transmittance exceeds 70% in the wavelength range of 2.56-2.95 mu m and 3.93-4.97 mu m. The extinction ratio exceeds 20dB in 2.5-5.5 mu m band. The mid-infrared polarizer has potential applications in fields such as polarization detection, communication, and spectral analysis.