Effect of Monomers on the Holographic Properties of Poly(vinyl alcohol)-Based Photopolymers

Based on the poly(vinyl alcohol) (PVA) system, photopolymers were prepared with two different monomers: N-vinylpyrrolidone (NVP) and acrylamide (AM). The maximum diffraction efficiency of the photopolymers was more than 85%, and the maximum sensitivity was 17.77 × 10–3 cm2/mJ. The optimized photopolymer with high diffraction efficiency and high photosensitivity can achieve both the recording and reproduction of reflection holography and the recording and reproduction of transmission holography. At the same time, the effects of monomer on holographic properties of photopolymers were studied. It was found that the reactivity and migration rate of the monomer worked together on the polymerization rate, which affected the holographic properties of the photopolymer. To verify the influence of the structure of NVP and AM on the reactivity and migration rate, the transmittance and the real-time diffraction efficiency measurements were innovatively used. The NVP with high electron cloud density was more reactive, while the AM with low molecular weight and simple molecular structure had a faster migration rate.