Improving performance oftwo‐stagephotopolymers for volume holographic recording by fluorinatedepoxy‐amine cross‐linkedmatrices

Abstract

AbstractHost matrices play an important role in the volume holographic gratings formation of photopolymers. In this study, a series of fluorinated epoxy resin (FTGE) with low refractive index (1.44–1.46) are synthesized and characterized by nuclear magnetic resonance spectra (1H NMR,19F NMR) and fourier transform infrared spectra (FTIR). Fluorinated epoxy‐amine cross‐linked matrices are formed at room temperature and their thermal polymerization properties are investigated through real‐time FTIR and thermogravimetric analyses (TGA). Using the fluorinated epoxy‐amine as host matrices, holographic photopolymers are fabricated. The influence of different kinds (Prop‐FTGE, Buta‐FTGE, and Penta‐FTGE) and weight ratios (0%, 8%, 16%, and 23%) of FTGEs on holographic performances of the photopolymers are explored. The results show that the sample with 23% Prop‐FTGE has the most excellent holographic optical characteristics. 0.5 mm thick sample with 23% Prop‐FTGE reaches 91% diffraction efficiency within 80 mJ/cm2exposure dosage, and gets a 2000 lp/mm Bragg volume grating with 0.24° angular selectivity. Meanwhile, under a single pulse exposure mode (150–200 ps pulse width, 25 mJ/cm2exposure dosage), a grating with 4.4% diffraction efficiency is obtained, which proves the ultrafast response and recording capability of the sample.