Holographic Data Storage
This chapter provides a summary of some of the main features of holographic data storage systems (HDSS) and in particular the demands on the holographic material, recording, and reconstruction process. Work on HDSS started with the advent of the laser in the 1960s, however, the lack of suitable optical interface devices such as spatial light modulators (SLM) and camera arrays as well as holographic recording materials with the right characteristics prevented development. In the Fourier transform hologram arrangement, the SLM aperture is placed at the front focal plane of a lens and the holographic recording material at the back focal plane. The image resolution of an optical system used to holographically record and reconstruct a page of information will be lower than a serial “bit-wise” system. A number of multiplexing methods have been developed and demonstrated for holographic data storage systems that take advantage of the volume selectivity, directionality, and wavefront matching properties of the holographic process.