We propose a new optical implementation of orthogonal phase-code multiplexing in which an arbitrary phase shift of θ or θ +π is used in the reference beam instead of 0 or π as in the conventional method. To compare the new and the conventional methods, we employ a 2-bit orthogonal phase code and store two binary-data images in a BaTiO<sub>3</sub> crystal with each method. We also employ numerical methods to simulate the 2-bit phase-code multiplexing and show that the signal-to-noise ratio in the restored images is improved by more than one order of magnitude in the new method in our experimental conditions.
© 2001 Optical Society of America
(090.4220) Holography : Multiplex holography
(090.7330) Holography : Volume gratings
(190.5530) Nonlinear optics : Pulse propagation and temporal solitons
(210.2860) Optical data storage : Holographic and volume memories
Yeon H. Lee and Seung-Dae Sohn, "Optical implementation of orthogonal phase-code multiplexing," Opt. Lett. 26, 1990-1992 (2001)