Pattern analysis for tilt servo control in holographic data storage system

Abstract

Today many media of information storage device are formed as disks. Hence, next generation removable data storage media are shaped as disk types too. The holographic data storage system also uses a disk type photopolymer media. And then, holographic data storage system is most advanced optical memory system. In 1948, Dennis Gabor made the insightful observation that the phase formation in a diffracted wavefront could be recorded by interference with a coherent background. It was not until the early 1960s with the invention of the laser that the technology became practical for storing and retrieving images, and the concepts of holographic data storage were established by van Heerden. In his seminal paper in 1963 on the theory of optical information storage in solids, van Heerden postulated that the recording of interference patterns in a three-dimensional medium could be used as a means of storing and retrieving information (Holographic data storage, Springer, New York, 2000). Tracking servo and tilt servo control are very important research in holographic data storage system. In this paper, we propose intelligent servo control by fuzzy rules in holographic data storage system. Hence, we have found pattern of tilt servo control in holographic data storage system through fuzzy system. Fuzzy rules were generated by subtractive clustering algorithm for controlling tilt servo. Therefore, we control tilt servo using fuzzy rules in holographic data storage system. Consequently, practical pattern of tilt servo control was found by intelligence algorithm in holographic data storage system (Holographic data storage, Springer, New York, 2000).