Applied principles as well as recording components of holograms are elaborated in this up-to-date book. It presents an overview on current developments in the advancement of a broad range of holographic recording substances comprising of ionic liquids in photopolymerisable materials, azo-dye containing materials, porous glass and polymer composites, amorphous chalcogenide films, Norland optical adhesive as holographic recording material and organic photochromic materials. Comprehensive evaluation of collinear holographic information storage and polychromatic rebuilding for volume holographic memory has also been discussed. New holographic devices, as well as utilization of holograms in security and signal processing have also been presented in this book.