Interferometric key readable security holograms with secrete-codes

Pramana

D Mohan²  A K Aggarwal1¹  Raj Kumar¹ 

[1] Coherent Optics Division, Central Scientific Instruments Organisation, Sector 30, Chandigarh 160 030, India$$;Department of Applied Physics, Guru Jambheshwar University of Science & Technology, Hisar 125 001, India$$

关键词: Optical security;    authenticity verification;    security hologram.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

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.

【 授权许可】

Unknown