Geometrical phase image encryption obtained with space-variant subwavelength gratings Academic Article uri icon

abstract

  • An optical encryption method based on a geometrical phase produced by space-variant polarization manipulation is presented. The decrypted picture is retrieved either by a polarization measurement of the beam emerging from the encrypted element or by a single intensity measurement of the beam transmitted through the encrypted element followed by an optical key element. Both elements are realized by use of computer-generated space- variant subwavelength dielectric gratings. Theoretical analyses of the optical concept are presented along with experimental results.

publication date

  • January 1, 2005