Photopolymerization is commonly used for the solidification of materials in a liquid state. Here we use the method to stabilize a large number of topological defects in nematic liquid crystals. We experimentally visualize the director field which consists of defects of strength ±1. For a very low concentration of a reactive monomer, the array structure cannot be maintained when the field is switched off. However, to our surprise, a reproducible grid-like texture can be generated even if a high-frequency electric field is applied.
