Research On The Technology Of Double Random Phase Codes And Wavelength Encrypted Optical Holographic Storage

Holographic data storage systems have the potential to provide high storage densities and high data rates, thus making them attractive candidates for storage applications. There are a variety of holographic storage technologies published in magazines recently. Totally, they can be divided into two methods: (1).wavelength multiplexed holographic data storage; (2).angular multiplexed holographic data storage. Althouge these two technologies are differrent in mechanism, but there are two common features: (l).many pages of data are multiplexed hi the same volumn of the storage medium,which leads to a large storage capacity; (2).accessing data in parallism in term of page,which leads to fast data rate. Because this technology is becoming mature in laboratory, there is a promising future when people apply it in national information inrrastracture construction, superlarge capacity database, parrellel computing, coventional entertainment indurstry. As it comes down to information, security is absolutely necessery. Although encrypted optical holographic storage such as double random phase encoding and encrypted orthogonal phase encoding have been validated to be correct, but they can apply only one pace of encryption, which can not meet the need of encrypting the very inportant informations. Thus in this paper, a novel double encryption technology is presented. It can not only encrypt data with double phase codes, but also do it with wavelength. If one wants to retrive the encryping datable or she must know the phase keys and wavelength keys simultaniously, otherwise, the reconstructed data will be white noise like. In order to accurately, explicitly illustrating this technology, this paper is divided into five chapters: 1.optical holographic storage system. This chapter introduces the basic configuration and basic principle of optical holographic storage system, and discusses the primary reasons that affect the fidelity of the data, puts forward some methods overcoming noise. 2.optical information channel of holographic storage system. This chapter discusses two models of optical information channel of holographic system: intensity model and amplitude model, and discusses some methods overcoming noises by use of these two models. S.encypting holographic data storage based on orthogonal-phase-code multiplexing. This chapter introduces one technique which based on encrypting the access ofstorage data, this can be done by coding the phase of reference beams by use of orthogonal-phase-code. 4.double phase-encoded holographic storage. This chapter introduces one method that encrypts the data directly, which can be done by placing two phase masks on the input plane and FP plane respectively. When one wants to retrive the data, he must have the same mask placed on the FP plane,otherwise the data can not be reconstructed. 5.encrypted opticalstorage with wavelength-key and random phase codes.This paragraph presents a novel encrypted holographic storage system in combination of wavelength based on double phase codes.lt is not only inquired into in theory in detail, but also proved to be validate by computer simulation.