Plasmonic laser printing for ink-free color decoration

Here we show a method of color printing on nanoimprinted plasmonic metasurfaces [1] using laser post-writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures [2]. This leads to melting and reshaping of the imprinted 20nm Al structures embedded in plastics. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different color appearances can be created. Color printing by this technology has several advantages over dye technology: ink/toner-free, sub-wavelength resolution and the production of bright and non-fading colors. This technology creates a laser printer capable of producing images with a resolution of 127,000 DPI. It will be possible to save data invisible to the naked eye. This includes serial numbers or bar codes of products and other information. It can also be used on a larger scale to personify products such as mobile phones with unique decorations, names, etc‥ This laser technology may create environmentally sound color printing solutions and simplify the production for consumer products.