Improvement of optical data storage using bacteriorhodopsin and optical phase code

Abstract

In this dissertation, optical data storage system using bacteriorhodopsin as new material and optical phase code to reduce interpixel crosstalk noise is developed to enhance the performance of the system. In comparison with other systems designed up to now, the suggested system shows low reconstruction error as well as uniform spectrum in Fourier domain. Bacteriorhodopsin for holographic data storage and optical informaition processing system is investigated and optical spatial CDMA system is suggested analytically and experimentally. To reduce interpixel crosstalk noise which has been important problem in holographic data storage system with finite aperture size, GS(Gerchberg-Saxton) algorithm and EBP(Error Back Propagation) algorithm are used. With these algorithms, optimized phase codes can be implemented to redistribute the spectrum in Fourier domain. Uniformity of spectrum in Fourier domain is also considered with error reduction in obtaining optimized phase codes. Uniformity of spectrum in Fourier domain is important factor in holographic data storage system for diffraction efficiency. And also, FrFT(fractional Fourier transform) has been applied to obtain lower reconstruction error and more uniform spectrum in Fourier domain. Several different fractional orders have been tried for better performance of the system.