New ways in creating pixelgram images

Radu Malureanu*, Enzo Di Fabrizio

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review


Since the diffraction gratings were invented, their use in various security systems has been exploited. Their big advantage is the low production cost and, in the same time, the difficulty of replicating them. Most of the nowadays security systems are using those gratings to prove their originality. They can be seen on all the CDs, DVDs, most of the major credit cards and even on the wine bottles. In this article we present a new way of making such gratings without changing the production steps but generating an even more difficult to be replicated item. This new way consists not only in changing the grating period so that various false colours can be seen, but also their orientation so that for a complete check of the grating it should be seen under a certain solid angle. In the same time, one can also keep the possibility to change the grating period so this way various colours can be seen for each angle variation. By combining these two techniques (changing period and changing the angle ones) one can indeed create different images for each view angle and thus increasing the security of the object. In the same time, as can be seen, from the fabrication point of view no further complications appear. The production steps are identical, the only difference being the pattern. The resolution of the grating is not increased necessarily so neither from this point of view will complications appear.

Original languageEnglish (US)
Article number64020F
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 2006
Externally publishedYes
EventOptics and Photonics for Counterterrorism and Crime Fighting II - Stockholm, Sweden
Duration: Sep 11 2006Sep 12 2006


  • Diffraction gratings
  • Security systems

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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