Chapter 21 - Nanoparticle Doped Photopolymers for Holographic Applications

Abstract

This chapter presents a review of holographic recording materials and their main areas of application. During holographic recording the interference pattern formed in the intersection area of two coherent waves is recorded in a photosensitive medium. As the illuminated material is photosensitive, its optical properties change, and the variations of the intensity of the recording light field are copied by a variation of the absorption coefficient, the refractive index, or of the thickness of the recording medium. The basic idea behind the concept of the photopolymerisable nanocomposites is to introduce nanodopants with significantly different refractive index from that of the host material and to achieve redistribution of the nanodopants during the holographic recording. Such redistribution causes significant increase in the ultimate refractive index modulation and, consequently, improvement of the dynamic range of the material. A large variety of the available holographic recording materials include silver-halide emulsions, dichromated gelatine, photoresists, photothermoplastics, photochromics, photorefractives, photopolymers, and azodye-containing polymers. Each group of materials has different characteristics and is more suitable for a specific application. For instance silver-halide emulsions and dichromated gelatin are suitable for art holography as they posses extreme sensitivity and very high spatial resolution The variety of holographic applications constantly grows with the advances in optics, optoelectronics, and holographic recording materials design. This review demonstrates that photopolymerisable nanocomposite design is a flexible and promising approach for improving the properties of holographic recording materials.