Journal
OPTICS COMMUNICATIONS
Volume 283, Issue 2, Pages 243-248Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.optcom.2009.10.011
Keywords
Dot-matrix hologram; Intersecting angle; Moire-pattern; Two-beam writer; Anti-counterfeiting
Categories
Funding
- National Science Council of the Republic of China [NSC 97-2221-E-262-005-MY2]
Ask authors/readers for more resources
Three features about the intersecting state of two gratings are used to identify dot-matrix holograms created by two-beam writers in this paper. The first feature is the intersection angle of the fringes of two gratings. The second feature is the ratio of the pitches of two lowest-order moire-patterns formed by overlapping two gratings. The third feature is the length ratio of the two diagonal lines of a parallelogram constructed by two neighboring fringes of a first grating and two neighboring fringes of a second grating. All the three features are equivalent, i.e. they are all relative to the intersection angle of two gratings. Because the grating orientations of grating dots cannot be accurately reproduced for the orientation uncertainties of the components used by a two-beam writer, the intersection angles of the gratings of grating dots cannot be easily counterfeited. Therefore, the proposed methods are practical and feasible for the anti-counterfeiting applications of dot-matrix holograms. (C) 2009 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available