Volume Holograms in Photopolymers: Comparison between Analytical and Rigorous Theories |
| |
Authors: | Sergi Gallego Cristian Neipp Luis A. Estepa Manuel Ortu?o Andrés Márquez Jorge Francés Inmaculada Pascual Augusto Beléndez |
| |
Affiliation: | 1.Department of Physics, Systems Engineering and Signal Theory, University of Alicante, Apartado 99, E03080 Alicante, Spain; E-Mails: (C.N.); (L.A.E.); (M.O.); (A.M.); (J.F.); (A.B.);2.University Institute of Physics Applied to Sciences and Technologies, University of Alicante, Apartado 99, E03080 Alicante, Spain;3.Department of Optics, Pharmacology and Anatomy, University of Alicante, Apartado 99, E03080 Alicante, Spain; E-Mail: |
| |
Abstract: | There is no doubt that the concept of volume holography has led to an incredibly great amount of scientific research and technological applications. One of these applications is the use of volume holograms as optical memories, and in particular, the use of a photosensitive medium like a photopolymeric material to record information in all its volume. In this work we analyze the applicability of Kogelnik’s Coupled Wave theory to the study of volume holograms recorded in photopolymers. Some of the theoretical models in the literature describing the mechanism of hologram formation in photopolymer materials use Kogelnik’s theory to analyze the gratings recorded in photopolymeric materials. If Kogelnik’s theory cannot be applied is necessary to use a more general Coupled Wave theory (CW) or the Rigorous Coupled Wave theory (RCW). The RCW does not incorporate any approximation and thus, since it is rigorous, permits judging the accurateness of the approximations included in Kogelnik’s and CW theories. In this article, a comparison between the predictions of the three theories for phase transmission diffraction gratings is carried out. We have demonstrated the agreement in the prediction of CW and RCW and the validity of Kogelnik’s theory only for gratings with spatial frequencies higher than 500 lines/mm for the usual values of the refractive index modulations obtained in photopolymers. |
| |
Keywords: | holographic materials photopolymers volume holograms |
|
|