On a problem of the synthesis of binary nano-optical elements

This paper deals with optical security label identification technology as a part of augmented reality technology. Security labels are based on binary nanooptical elements and are photographed using a smartphone. Photographed images are interpreted as diffractive optical elements. Optical images formed by these diffractive elements are computed using the Fresnel approximation. These images are used to identify the security labels. A security label consists of a phase optical element whose microrelief height is of no more than 0.5 $\mu$m. Nanooptical elements are manufactured using electron-beam lithography. The optical security labels are resistant against microrelief damages and can withstand partial loss of an image. The optical elements developed can be used to protect and identify banknotes, documents, etc.