Femtosecond laser nanoprinting of anisotropic plasmonic surfaces: coloration and anticounterfeiting

An anisotropic plasmonic surface of nanoellipsoid arrays is successfully fabricated on an Au film using slit-shaping-based femtosecond laser nanoprinting. The size and orientation of the nanoellipsoid can be exquisitely and flexibly controlled by adjusting the width and direction of the slit and the laser pulse energy. By dark-field optical micro-spectroscopy, anisotropic plasmonic color rendering as well as resonant light scattering from the lateral and vertical modes are experimentally and theoretically investigated in the visible spectral range. In addition, prospective use in the fields of steganographic encryption and multidimensional optical multiplexing is also proposed.