METHOD FOR SYNTHESIZING PLANAR DIFFRACTIVE OPTICAL ELEMENTS

The micro-optical system for the formation of visual images is a tool primarily intended for authentication of products and can be efficiently used to protect banknotes and securities.According to the invention formula, the micro-optical system has the form of a flat reflecting single-layer phase element, which consists of fragments of multigradational flat axial Fresnel lenses with parabolic phase function and of diffraction gratings. The design of the optical element makes it possible to form 3D wireframe images consisting of edges. When the micro-optical system is illuminated by a point source, it creates at diffraction angles smaller than 60° the effect of the alternation of two 3D images. At diffraction angles greater than 60° the observer sees another 2D color image over the entire region of the micro-optical system.The claimed combination of important features of the invention ensured the achievement of the technical result consisting in the expansion of the capabilities of visual control and in the enhancement of the protection of the micro-optical system against counterfeiting. The micro-optical system of the formation of visual images can be implemented using available standard equipment.