The security verification method using a transform random phase mask as an optical mark bonded to a document or other product is proposed. This mask consists of separated and shifted fragments of a reference phase mask. If the transformed and the reference masks are entered into an optical correlator, the autocorrelation peaks series is produced on the correlator output. The distances between peaks and the peak intensities were used to produce the feature vector. Identification of the document or other product takes place if the feature vector and the reference feature vector coincide. The procedure of the transformed mask generation and the process of the peaks' producing in a conventional joint transform correlator were considered. The advantages of transformed mask applications in optical correlators are discussed. The joint transform correlator experimental setup containing the spatial light modulator PRIZ was designed and the optimal conditions to produce the autocorrelation peaks were found.

Date Published: 9 October 1998
PDF: 11 pages
Proc. SPIE 3466, Algorithms, Devices, and Systems for Optical Information Processing II, (9 October 1998); doi: 10.1117/12.326790

Published in SPIE Proceedings Vol. 3466:
Algorithms, Devices, and Systems for Optical Information Processing II
Bahram Javidi; Demetri Psaltis, Editor(s)