Photomask, and photoalignment film and diffractive element produced using the photomask

Abstract

Provided are a photomask that has high light resistance and a fine structure and that can be easily produced, and a photoalignment film and a diffractive element produced using the photomask. The photomask of the present invention includes a supporting substrate and a structural birefringence layer arranged on the supporting substrate. The structural birefringence layer has a structure in which, in a plan view, repeating unit structures are periodically arranged. The repeating unit structures each have a structure in which, in a plan view, optical unit structures with slow axes at different azimuthal angles are arranged along an arrangement direction of the repeating unit structures. The optical unit structures each have a structure in which regions with different refractive indices are alternately arranged. The slow axes of the optical unit structures are each not perpendicular to the arrangement direction in a plan view.

Dependencies are inferred from the claim text.