ANTIREFLECTION FUNCTIONAL ELEMENT, OPTICAL ELEMENT, OPTICAL SYSTEM AND OPTICAL APPLIANCE

摘要

PROBLEM TO BE SOLVED: To provide an antireflection function element having an excellent antireflection function by a fine periodical structure and having durability of the fine periodical structure. SOLUTION: The antireflection function element is produced by forming a periodical structure 2 having a smaller period than the wavelength of the incident light on the surface of a base material 3 and then an additional layer 4 having a lower refractive index than the refractive index of the base material on the periodical structure. Or, a periodical structure with a smaller period than the wavelength of the incident light is also formed in the additional layer 4.