Investigation of high thickness holographic gratings in acrylamide-based photopolymer
Abstract
We studied the holographic characteristics of acrylamide-based photopolymer layers ranging in thickness from 300 to 1000 . Scattering patterns of various materials were presented, and both transmittance and scattering ratio were measured. Then, theoretical and experimental Bragg selectivity curves of two samples with thicknesses of 300 and 510 were analyzed, demonstrating the effective optical thickness inside photopolymer, which was responsible for the width of Bragg selectivity curve. Through the simulation for the spatial dynamics of refractive index distribution inside materials with different thicknesses, the attenuation of grating along the direction of thickness inside photopolymer was presented. Moreover, the photo-induced polymer chain length was evaluated, and a growing tendency of polymer chain length as increasing depth of material thickness was presented for the first time, in other words, there were polymers with longer chain length in deeper layer of material.
