SU-8 nanoimprint fabrication of wire-grid polarizers using deep-UV interference lithography

We describe a new fabrication method for making wire-grid polarizers for the visible and near-IR based on deep-UV interference lithography, nanoimprint, and glancing angle deposition. We fabricated aluminum wire grids with periods ranging from 375 to 230 nm with heights from 145 to 110 nm, respectively. The measured extinction ratio was as high as 220:1 at 1064 nm. The performance of the polarizer is limited by the roughness and porosity of the Al film and the underlying SU-8 structure. This method allows patterning of wire grids on any substrate material, which makes this an attractive method for fabricating wire-grid micropolarizers in a timely and cost-effective manner.