Identification of a replicable optical security element using laser speckle

Optics and Laser Technology. 2024. Vol. 175. Article 110725.

Smolovich A. M., Frolov A. V., Klebanov L. D., Laktaev I. D., Orlov A. P., Smolovich P. A., O.V. Butov

An optical security element containing an area of random rough relief is proposed. It combines the low cost of
mass replication inherent in traditional security holograms with the impossibility of holographic copying, when
the wave restored by the hologram is rewritten as a copy of this hologram. The proposed optical element is also
protected from contact and photographic copying. Laboratory samples of optical elements were obtained by
taking replicas of a rough surface. Identification of the authenticity of optical elements was demonstrated by
calculating the cross-correlation of speckle patterns produced by coherent light scattered off different replicas. It
is assumed that the proposed security elements can be mass-produced on standard equipment for embossing
security holograms.

Keywords: correlation, Authenticity identification, Optical security element, Speckle, Random relief