Holographic memory encrypted by an optical random-phase key and decrypted by either the original phase key or a duplicate key is proposed and demonstrated. The duplicate key is made by recording the encryption wave front with angle multiplexing during writing of the hologram. The amount of three-dimensional shifting that is tolerable in the duplicate key is analyzed.
© 2004 Optical Society of America
(090.0090) Holography : Holography
(090.7330) Holography : Volume gratings
(190.5330) Nonlinear optics : Photorefractive optics
(210.0210) Optical data storage : Optical data storage
(210.2860) Optical data storage : Holographic and volume memories
Wei-Chia Su, Ching-Cherng Sun, Yu-Cheng Chen, and Yueh Ouyang, "Duplication of Phase Key for Random-Phase-Encrypted Volume Holograms," Appl. Opt. 43, 1728-1733 (2004)