DIFFRACTION ELEMENT AND OPTICAL DEVICE

摘要

A diffraction element having a large wavelength separating effect with a high diffraction efficiency despite its excellent mass-productivity using a simple process. A diffraction element (30) formed on a transparent substrate (301), and being protruded and recessed in section with protruded portions forming symmetrical rectangular lattices (302), wherein one cycle of a lattice is equal to or smaller than the wavelength of an incident light, and the diffraction element is used with a light entering obliquely the lattice formed surface of the diffraction element (30).