We introduce the technique of wavelength multiplexing into a double random-phase encoding system to achieve multiple-image encryption. Each primary image is first encrypted by the double phase encoding method and then superposed to yield the final enciphered image. We analyze the minimum separation between two adjacent multiplexing wavelengths through cross talk and the multiplexing capacity through the correlation coefficient. Computer simulations are performed to demonstrate the concept. This technique can be used for hiding multiple images as well.
© 2005 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(070.2580) Fourier optics and signal processing : Paraxial wave optics
(070.4560) Fourier optics and signal processing : Data processing by optical means
(100.0100) Image processing : Image processing
Guohai Situ and Jingjuan Zhang, "Multiple-image encryption by wavelength multiplexing," Opt. Lett. 30, 1306-1308 (2005)