Morphological Studies of Bragg Reflection Gratings Written in Holographic Polymer Dispersed Liquid Crystals by Thiol-Ene Photopolymerization (Preprint).

摘要

Recently, a new photopolymerization system for writing visible light initiated thiol-ene based H-PDLC Bragg reflection gratings was developed. Using this new method, Bragg reflection gratings were written with notch wavelengths out into the NIR. The aim of the present work is to determine the grating parameters like spacing, LC width, polymer width and droplet density from morphological studies and compare with those obtained from optical measurements. The electro-optical performance of the gratings is also interpreted in terms of the morphology. The morphological properties of these gratings were obtained from TEM and cryo-SEM microscopy. The spacing, LC droplet sizes and droplet densities correlate very well with the optical and electro-optical performance of the gratings.