Encryption of a volume hologram by complementary input image and binary amplitude mask

A novel volume-hologram encryption system is proposed, in which the stored binary image can be restored only by the correct random binary amplitude mask. In our system the encryption is done by overlapping two holograms in the same volume of the crystal; one is the hologram of the original binary image and the other is that of the complementary image. The principle of the system is explained with schematic diagrams and then the experimental data is shown.