Dynamical behaviour of the optical properties of photopolymers and the Lorentz-Lorenz formula

Photochemical variations of the refraction index of dielectrics are explored using the Lorentz-Lorenz formula. The scope of this analysis is restricted to photoinitated chemical reactions in the optical range that originates small differences in the refraction index, assuming that the dielectric constitutes an approximately constant background. These types of systems are relevant when considering the optical macroscopic response of holographic recording materials. Relations arising from a photopolymer are analysed in detail.