• Interferometric key readable security holograms with secrete-codes

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      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/068/03/0443-0450

    • Keywords

       

      Optical security; authenticity verification; security hologram.

    • Abstract

       

      A new method is described to create secrete-codes in the security holograms for enhancing their anti-counterfeiting characteristics. To imitate these codes is difficult as pure phase objects having complex phase distribution function are used to modulate the object beam that is recorded in conjunction with an encoded interferometric reference beam derived from a key hologram. Lloyd's folding mirror interferometer is used to convert phase variations of the reconstructed wave-front into an intensity pattern for hologram authenticity verification. Creating the secrete-codes through an interferometric reference beam from the key hologram facilitates a multi-stage authenticity verification as well as easy repositioning of the security hologram through a specific Moiré pattern generated during the verification process.

    • Author Affiliations

       

      Raj Kumar1 D Mohan2 A K Aggarwal1

      1. Coherent Optics Division, Central Scientific Instruments Organisation, Sector 30, Chandigarh 160 030, India
      2. Department of Applied Physics, Guru Jambheshwar University of Science & Technology, Hisar 125 001, India
    • Dates

       
  • Pramana – Journal of Physics | News

© 2017 Indian Academy of Sciences, Bengaluru.