US Patent 7256947 Optical element having minute periodic structure

An optical element is disclosed which has a reflection suppressing function and a color balance correcting function in a minute periodic structure. The optical element has a base member and a minute periodic structure which is provided on a surface of the base member and has a period smaller than a wavelength of incident light on the optical element. The minute periodic structure has a characteristic that the reflectance of light a first wavelength on a short wavelength side in a wavelength range of the incident light is lower than the reflectance of light at a second wavelength on a long wavelength side in the wavelength range of the incident light.