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      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/070/01/0131-0139

    • Keywords

       

      Holograms; security holograms; optical security; extended fractional Fourier transforms.

    • Abstract

       

      This paper describes a simple method for making dual beam encoded extended fractional Fourier transform (EFRT) security holograms. The hologram possesses different stages of encoding so that security features are concealed and remain invisible to the counterfeiter. These concealed and encoded anticounterfeit security features in the security hologram can only be read through a key hologram. Key hologram also facilitates in-built repositioning of security hologram. The method of fabrication, the principle of reconstruction and the experimental results are presented.

    • Author Affiliations

       

      Amit K Sharma1 2 D P Chhachhia1 D Mohan3 A K Aggarwal1

      1. Coherent Optics Division, Central Scienti¯c Instruments Organisation, Sector 30, Chandigarh 160 030, India
      2. Department of Applied Science, IIMT Engineering College, Meerut 250 001, India
      3. Department of Physics, Panjab University, Chandigarh 160 014, India

    • Dates

       
      Published
      January 2008
      Manuscript received
      16 January 2007
      Manuscript revised
      21 August 2007
      Accepted
      28 August 2007

  • Pramana – Journal of Physics | News

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      Posted on July 25, 2019

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