Itsunari Yamada

Abstract A reflective-type polarization wavelength filter was fabricated by anodizing a Ti grating film. This polarization filter consisted of a Ti film, an anodized titanium oxide film (thickness ${\sim}{{25}}\;{\rm{nm}}$), and a photoresist grating with a pitch of 410 nm. The reflectance was less than 10% for both polarizations at 490–675 nm at an incident angle of 9°.

Abstract An infrared wire-grid polarizer was fabricated using two-beam interference lithography, anisotropical etching of Si in KOH solution, and thermal evaporation of Al. Consequently, an infrared wire-grid polarizer with a 1-µm-pitch and 195-nm-thick Al grating could be fabricated on the Si grating. The transmittance of transverse magnetic polarization was greater than 48% at 10-µm wavelength, and the extinction ratio was over 22 dB at this wavelength.