Sharma, A.K. and Chhachhia, D.P. and Mahajan, C.G. and Aggarwal, A.K. (2008) Dual beam encoded extended fractional Fourier transform security hologram with in-built repositioning. PRAMANA- journal of physics, 70 (1). pp. 131-139. ISSN ISSN : 0304-4289
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Abstract
This paper describes a simple method for making dual beam encoded ex-tended 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.
Item Type: | Article |
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Uncontrolled Keywords: | Holograms; security holograms; optical security; extended fractional Fourier transforms |
Subjects: | CSIO > Optics |
Divisions: | Photonics Instrumentation |
Depositing User: | Ms T Kaur |
Date Deposited: | 23 Jan 2012 15:35 |
Last Modified: | 11 Apr 2012 11:20 |
URI: | http://csioir.csio.res.in/id/eprint/200 |
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