Improving longitudinal shifting selectivity of volume holographic optical elements by introducing a light pipe

We propose a new scheme to enhance the longitudinal Bragg selectivity of a volume hologram with use of a light pipe. Longitudinal shifting selectivity of the system is shown to be obviously enhanced in both experimental measurement and theoretical calculation. Such a technique is not only useful in the volume holographic 3-D imaging but also useful in the shift multiplexing holographic optical storage system.