DLIP holographic structuring: from basic concept to advanced monitoring methods and industrial scale production

Abstract

This study reports on the application of the Direct Laser Interference Patterning method for the fabrication of holographic motives. The advantages of this method over conventional laser processing methods in terms of resolution, flexibility and throughput are analyzed. It is showed that interference approach for formation of diffraction gratings provides faster fabrication speed together with enhanced visual effect of the structural colors. The control of the period of the formed patterns provided the ability to form exact structural colors, which preserved the visibility of the motives across the whole structured area at certain observation conditions. The capability to improve further the fabrication speed, required for several industrial applications, is demonstrated using a Roll-to-Roll hot embossing system, permitting to replicate holographic motives formed by DLIP on PET foils. Finally, the first tests of inline monitoring method are presented, which is proposed for controlling the quality of the imprinted structures.