A two-step exposure method with interleaved phase pages for recording of SQAM signal in holographic memory

Abstract

We have proposed a two-step exposure method (TEM) for recording spatial quadrature amplitude modulated (SQAM) signals in holographic memories. We consider two generation methods of the phase pages used in the TEM and investigate the reproduction accuracy of the SQAM signal. One of them is to produce the phase pages by arranging from the conventional two-phase pages alternately. We indicate that it is able to reduce the consumption of photopolymerizable monomers in the photopolymer effectively by using the phase distribution. It also suppresses the adverse effect on the reproduction accuracy of SQAM signal by intensity variation of the multiplexed holograms. Further, we propose the method to produce the SQAM signals by a one-shot recording based on the analysis.