Direct femtosecond laser printing of plasmonic colors and functional sensing elements

Abstract

Utilization of structural colors produced by nanosized optical antennas is expected to revolutionize the current display technologies based on an ink-jet or pigmentation-based color printing. Meanwhile, the versatile color-mapping strategy combining the fast single-step single-substrate fabrication cycle with low-cost scalable operation is still missing. In this paper we present lithography-free direct approach based on local femtosecond-laser ablative reshaping of the gold film with nJ-energy femtosecond laser pulses allowing plasmon-color printing at typical resolution up to 25000 dots per inch, well enough for current visualization demands. By controlling the only experimental parameter – applied pulse energy - various colors in scattering regime at lateral resolution approaching optical diffraction limit, can be reproduced via mixing various nanostructures having polarization- and shape-dependent localized plasmon-mediated scattering and adjusting their spacing to involve collective plasmon resonances. Possibility to tune the brightness of the isolated pixel is discussed. We believe the presented experimental demonstration will inspire and stimulate new efforts directed toward elaboration of pulsed-laser plasmon-color printing strategy for various applications including low-cost cryptography, security tagging and ultracompact optical data storage.