Polarization diffraction grating, method for manufacturing the same, and optical pickup apparatus using the polarization diffraction grating

Abstract

A polarization diffraction grating that enables the polarization direction of incident light and the occurrence direction of diffracted light to be freely selected without being restricted by the material of a substrate is provided. A polarization diffraction grating includes a transparent substrate, a polymer liquid crystal layer that is adhered onto the transparent substrate via an adhesive layer, and that has a first concavity/convexity structure that diffracts incident light formed on a face opposite to the adhesive layer, and an optically isotropic material layer provided to fill the first concavity/convexity structure. A second concavity/convexity structure made up of a plurality of stripe grooves disposed parallel to each other is further formed on the face of the polymer liquid crystal layer on which the first concavity/convexity structure is formed, and liquid crystal molecules in the polymer liquid crystal layer are oriented in the groove lengthwise direction of the second concavity/convexity structure.

Dependencies are inferred from the claim text.