3D Image Storage in Photopolymer/ZnS Nanocomposites Tailored by “Photoinitibitor”

We synthesize zinc sulfide (ZnS) nanoparticles with a diameter of ∼5 nm and formulate novel photopolymer/ZnS nanocomposites for holographic recording. By taking advantage of the photoinitibitor, composed of 3,3′-carbonylbis(7-diethylaminocoumarin) (KCD) and N-phenylglycine (NPG), with a capability of spatiotemporally tailoring the grating formation process, we successfully achieve high performance holographic photopolymer/ZnS nanocomposites with as high as 93.6% of diffraction efficiency (η), 26.6 × 10–3 of refractive index modulation (n1), 8.4 per 200 μm of dynamic range, and 9.8 cm/mJ of photosensitivity. In addition, for an aim of roughly describing the grating formation process, we establish a novel exponential correlation between the ZnS nanoparticles segregation degree (SD) and the ratio of photopolymerization gelation time (tgel) to holographic mixture viscosity (v). Finally, we reconstruct and display 3D images that are clearly identifiable to the naked eye through a master technique, opening a versatile class of potential applications in high capacity data storage, stereoadvertisements, and anticounterfeiting.