Diffractive optical element and an optical system having a diffractive optical element

摘要

A diffractive optical element for white light is composed of a plurality of layers of optical materials and has a relief pattern constituting a diffraction grating formed at least at one cementing interface between the two different optical materials. The grating height of the relief pattern constituting the diffraction grating is defined by the following formula:h=lambd/|n-n'|where h represents the grating height of the relief pattern constituting the diffraction grating; lambd represents the wavelength (here it is assumed that lambd<=450 (nm)); n represents the refractive index of the optical material abutting the interface from the object side for light of the wavelength lambd; and n' represents the refractive index of the optical material abutting the interface from the image side for light of the wavelength lambd.