
Publica
Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten. Laser-induced spatially-selective tailoring of high-index dielectric metasurfaces
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Berzins, J.; Indrišiūnas, S.; Fasold, S.; Steinert, M.; Žukovskaja, O.; Cialla-May, D.; Gečys, P.; Bäumer, S.M.B.; Pertsch, T.; Setzpfandt, F.
Abstract
Optically resonant high-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances are usually fabricated by means of planar technologies, which limit the degrees of freedom in tunability and scalability of the fabricated systems. Therefore, we propose a complimentary post-processing technique based on ultrashort (≤ 10 ps) laser pulses. The process involves thermal effects: crystallization and reshaping, while the heat is localized by a high-precision positioning of the focused laser beam. Moreover, for the first time, the resonant behavior of dielectric metasurface elements is exploited to engineer a specific absorption profile, which leads to a spatially-selective heating and a customized modification. Such technique has the potential to reduce the complexity in the fabrication of non-uniform metasurface-based optical elements. Two distinct cases, a spatial pixelation of a large-scale metasurface and a height modification of metasurface elements, are explicitly demonstrated.