Theory of polarization holography

Abstract

In this chapter, we shall examine first the principles of interference and holography and extend them to the concept of polarization holography. We shall study the specific character of the periodic anisotropic structures obtained by the holographic method, which we call polarization holograms. We shall show how their efficiency and their polarization properties depend on the choice of recording geometry and on the photoinduced anisotropy in the materials. Since the formation of linear anisotropy is more common and more pronounced in photoanisotropic materials known at the moment, we first consider polarization holography in materials with linear anisotropy only. Then we extend the consideration to materials with both linear and circular anisotropy. The appearance of relief gratings on the surface of polarization holograms is also taken into account. Plane-wave interference and holography The holographic method was first proposed by Denis Gabor in 1948 [1] as a method for the reconstruction of wavefronts. Gabor proposed a two-stage process. The first stage is a two-dimensional photographic storage of the intensity distribution in the interference pattern of the signal wave ( S ) with a reference wave ( R ). At the second stage the reference wave illuminates the obtained photograph and reconstructs both the amplitude and the phase of the signal wavefront. The method was called “holography”, that is, “whole writing”. Later it was shown by Denisyuk [2] that, if three-dimensional (volume) materials are used to fix the interference field, the wavelength of the signal wave could also be restored.