Joint transform correlator optical encryption system: Extensions of the recorded encrypted signal and its inverse Fourier transform

GUSTAVO E. GALIZZI; CHRISTIAN CUADRADO-LABORDE

OPTICS COMMUNICATIONS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 353 p. 76 - 82

0030-4018

In this work we study the joint transform correlator setup, finding two analytical expressions for the  extensions of the joint power spectrum and its inverse Fourier transform. We found that an optimum efficiency is reached, when the bandwidth of the key code is equal to the sum of the bandwidths of the  image plus the random phase mask (RPM). The quality of the decryption is also affected by the ratio between the bandwidths of the RPM and the input image, being better as this ratio increases. In addition, the effect on the decrypted image when the detection area is lower than the encrypted signal extension was analyzed. We illustrate these results through several numerical examples.