Research Of Volume Holographic Storage And Correlation Recognition Based On Linbo 3 Crystal

With the rapid social development, the influence of information science and computer science on the life of people is increasing, and the people's request on storage technology is urgently. The traditional way of magnetic storage is already close to its physical limits. The volume holographic storage technology has a lot of advantages such as the high storage capacity, short access time and fast data transfer rate, so people pay more and more attention to it and do a lot of research on it , The volume holographic storage have great prospects, especially in information retrieval and large capacity image recognition and so on.This article mainly does research of volume holographic storage and correlative recognition which uses the photorefractive effect with LiNbO3 crystals as the storage medium. There are some improvements on the traditional volume holographic. In the holographic experiment, an external strong electric field, which will cause the change of the gratings'structure inside the crystal, is added on the both sides of the LiNbO3 crystal. We research the dependence of the diffraction efficiency on the changed external electric field. By comparing with traditional diffraction efficiency and the Bragg equation, we get the corresponding relation between the diffraction efficiency and the changed electric filed.Because of the existence of the noise in the volume holographic storage images, it will lead to tremendous inconvenience in practical application. In order to keep secret in many areas such as in military etc, we must consider the images'safety and fidelity. Since RS code has a good error correction ability, in this article we adopt RS code and Matlab soft to simulate the images used in the volume holographic storage. In the experiment, we get reconstructed images successfully and efficiently decrease the bit error rate. Therefore, the encoded mode provides good reference means for the information security.We employ three layers wavelet transform to decompose and reconstruct the image, and get three high frequency feature extraction by choosing the best wavelet base. In addition, we establish the total three high frequency feature extraction by adding ten images'high frequency feature extraction. After fulfilling volume holographic and correlation recognition experiments, we get the reconstructed images and the correlation peaks successfully. By this way we can enlarge the storage capacity.