Cylindrical computer-generated hologram for displaying 3D images.

A method for computing and synthesizing a diffractive optical element (DOE) on a cylindrical surface is proposed. The computer-generated hologram is a phase reflecting DOE, which, when illuminated with white light, displays a 3D image with a 360° viewing angle. The optical element consists of hogels with the size of about 50 microns, which are partly filled with diffraction gratings of various periods and orientations. The DOE is synthesized using electron-beam technology with a resolution of 0.1 micron. Flat optical elements can be replicated using standard equipment employed to produce rainbow relief holograms. When placed on a cylindrical surface, optical elements made on a flexible base display a 3D image observed at 360° viewing angles. The DOE developed can be used to protect objects against counterfeit.