Optimizing the speckle size of reference beam to improve the performance of high-density volume holographic storage

In this paper, the dependences of both multiplexing selectivity and diffraction efficiency in the holographic data storage on the speckle size are derived respectively. Based on these dependences, a new characteristic parameter of speckle holographic storage is defined as the optimization criterion. Then the speckle size is optimized to compromise its influence on the multiplexing selectivity and the diffraction efficiency. The simulated calculation results show that the speckle size should be neither too big nor too small in order to get the best performance of the high-density volume holographic storage with speckle reference beam. In addition, the intensity ratio between the signal beam and the illumination beam that is used to produce speckle reference beam also influences the optimization.