The investigation of angular separation for holographic angle multiplexing

Abstract

In angle multiplexing, the angle between the reference light and the object light is slightly changed in different recordings. In reconstruction, only the reference beam with an accurate angular position can retrieve the corresponding object beam due to the characteristics of Bragg condition. Accordingly, a suitable angular separation of the reference beam should be decided for angle multiplexing. A larger angular separation will decrease the storage density, and a smaller angular separation will increase the cross-talk noise in small bi-angles. In general speaking, only one condition of full angle of lights is involved to calculate the angular separation with coupled-mode theory or with experiment. Thus the angular separation is fixed in the whole procedure of angle multiplexing. As a result, the angular separations of most multiplexed holograms are either larger or smaller. Only one hologram is multiplexed in the critical angular condition. In this paper, angle multiplexing with different angular separations were performed to quantitatively demonstrate the effect. The possible method to deal with the issue was also proposed.