A new model to describe the influences of chemical processing on thick holograms is presented. The model is based on three hypotheses about the behaviour of holographic recording material during processing. Thickness variations and shear-type effects that are due to…

We present two methods, interferometry at the zero spatial frequency limit and analysis of diffracted orders for very low spatial frequency gratings, to characterize photopolymers with dispersed nematic liquid crystals. These methods provide us with real time information about the…

Bleached holograms are one of the most interesting techniques used to produce phase holograms of high quality on photographic emulsions. Of particular interest is the method of fixation-free rehalogenating bleaching. Using Kogelnik's coupled-wave theory we shall obtain information about the…

We present an available and low cost technique for the production of binary-phase diffractive optical elements designed by digital methods. We produce binary-amplitude holograms making use of a high-resolution graphic device. They are used as binary masks which are copied…

A statistical model is used to study the formation of noise gratings in holograms and the mechanism that causes radiation scattering in them. The theoretical model presented describes noise scattering in terms of diffraction due to the high number of…

A model is proposed which allows us to obtain the diffraction efficiency of photopolymeric materials with a nonlinear response to the refraction index, using the equations on the evolution of copolymerization reactions as a base. The photochemical material being analysed…

The response of a H-PDLC device is improved by means of a two-step method. First, component optimization—initiator system, crosslinker, and cosolvent—enables the diffraction efficiency of the hologram to be maximized. Second, the use of N-methyl-2-pyrrolidone in combination with N-vinyl-2-pyrrolidone prevents…

Optical densities before bleaching and final Lin curves of planewave phase holograms recorded in Agfa—Gevaert 8E75HD emulsions were measured for various combinations of developers (AAC, Pyrogallol and Catechol) and bleaching agents (R-9 and EDTA). To characterize the processing, the square…

Silver halide sensitized gelatin (SHSG) is an interesting technique for the production of holographic optical elements. It combines the high sensitivity of photographic emulsions with the well-known low scattering and high diffraction efficiency corresponding to dichromated gelatin. In this paper…

Bleached holograms are one of the most interesting techniques used to produce phase holograms of high quality on photographic emulsions. Of particular interest is the method of fixation-free rehalogenating bleaching. In this paper we will study the influence of the…