DIFFRACTIVE OPTICAL ELEMENT, METHOD FOR MANUFACTURING DIFFRACTIVE OPTICAL ELEMENT, AND LASER BEAM MACHINING METHOD

摘要

A diffractive optical element includes: a substrate having a first face and a second face; a diffractive structure section that is formed on the first face of the substrate, shaped in a rectangular form in a cross-sectional view of the diffractive structure section, and having an upper face and a plurality of protuberance portions; and a grid section that is formed of a dielectric material, formed on at least one of the upper face of the diffractive structure section and the second face of the substrate, and including micro protuberance portions that are smaller than each of the protuberance portions.