Fractional Fourier Transform Of Holographic Storage

The requirements for storage capacity and fast transfer rate haveincreased dramatically in the past decade, and are exploding especiallywith the popularity of the intemet and multimedia. Our needs for highcapacity, fast transferrate, and short access time appear to be insatiable.Optics and the basic principles of holography are a particularly attractiveway to meet these requirements and may well represent the storagesolution of the future. But the realization of holographic storage has beenfrustrated by the lack of availability of suitable system components, andperhaps most importantly, by the absence of recording materials thatsatisfied the stringent requirements of holographic storage. Recently thedevelopment of practical components for holographic systems removesmany of the obstacles that previously prevented the practicalconsideration of holographic storage and greatly enhances the prospectsfor holography to become a next generation storage technology. Apractically realizable, high capacity hologr aphic storage systemwith fasttransfer rates and low cost, removable recording media is vividlyportrayed. Fractional Fourier Optics becomes a new branch of themodern optics after the introduction of Fractional Fourier Transform(FRT)from mathematics to optics. It is regarded as the development andextension of Fourier optics. It not only makes us look at opticalpropagation, optical imaging and information processing from a newpoint, but also provides us a new tool to treat these problems. FractionalFourier Optics has been widely used in many fields of information processing and will be used more widely in the future.Based on the theory of Fractional Fourier Transform, we present anovel types of Fractional Fourier Transform of holographic storage andanalyze their principles and the results of the experiment and hope toprovide an effective way for the development of holographic storage.In chapter 1, at first, a simple overview is presented for the bringhistory back ground of holographic storage; In chapter 2, the basictheories of Fractional Fourier Transform are explicated. Especially, thedefinition of Fractional Fourier Transform, several optical devices ofFractional Fourier Transform and the relationship between fractionalFourier Transform and Fresnel diffraction, which form the theoreticalbasic of the works in the following chapters, are discussed in detail;In chapter 3, the basic theories of holographic storage are elaborated, whi-ch lay the foundation for the study of Fractional Fourier transform ofholographic storage: In chapter 4, based on the theory of FractionalFourier Transform, we deduced and analyzed the relationship betweenFractional Fourier Transform and Fresnel holographic storage and theexperimental results show the presented method is reliable.