Computer generated hologram optical element

摘要

A main object of the present invention is to provide a computer-generated hologram optical element with little decline of the image converting function even when a pollutant such as oil and water is adhered to the surface. To achieve the object, the present invention provides a computer-generated hologram optical element comprising: a transmission type Fourier transform hologram comprising a substrate, and an image converting layer formed on the substrate and having a function as a Fourier transform lens; a diffraction function layer disposed on the image converting layer of the transmission type Fourier transform hologram and having a certain refractive index difference with respect to the image converting layer; and a protection layer formed on the diffraction function layer.