Infrared Wire-Grid Polarizer with Antireflection Structure by Imprinting on Both Sides

We fabricated infrared wire-grid polarizers with an antireflection (AR) grating structure by the simultaneous imprinting on both sides of a low-toxicity chalcogenide glass (Sb–Ge–Sn–S system). Silicon carbide and glassy carbon plates were used as molds for the direct glass imprinting. A wire-grid polarizer of 100-nm-thick was produced by depositing Al obliquely on the grating. Although the transmittance of the chalcogenide glass substrate was 62–66% in the 8.5–10.5 µm wavelength range, the transverse magnetic (TM) transmittance of the fabricated element became higher than 70% owing to the AR structure. The extinction ratio was larger than 20 dB at 11 µm wavelength.