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Optical Engineering

Gratings of constantly varying depth for visual security devices
Author(s): Rene Staub; Wayne Robert Tompkin; Andreas Schilling
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Paper Abstract

Sinusoidal gratings of locally varying profile depth are incorporated into diffractive optically variable image devices (DOVIDs) for document security. The variation in profile depth is tailored to specific visual effects that can be readily authenticated. While the diffractive characteristics of these gratings depend very sensitively on the depth, the security of these DOVIDs is inherent to the diffractive structures insofar as the exact reconstruction of the original profile is required for the realization of the original visual effects. Sinusoidal gratings of locally varying profile depth are very resistant against copying by standard holographic techniques since these techniques are shown to lead to a loss of fidelity in profile form or depth.

Paper Details

Date Published: 1 January 1999
PDF: 10 pages
Opt. Eng. 38(1) doi: 10.1117/1.602064
Published in: Optical Engineering Volume 38, Issue 1
Show Author Affiliations
Rene Staub, Landis & Gyr Communications Corp. (Switzerland)
Wayne Robert Tompkin, Landis & Gyr Communications Corp. (Switzerland)


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