Tuning Collective Plasmon Resonances of Femtosecond Laser-Printed Metasurface

The optical response of properly excited periodically arranged plasmonic nanostructures is known to demonstrate sharp resonance features associated with high-Q collective modes demanding for various applications in light–matter interaction, filtering and sensing. Meanwhile, practical realization and replication of plasmonic platforms supporting high-Q modes via scalable inexpen-sive lithography-free approach is still challenging. Here, we justify direct ablation-free irradiation of Si-supported thin Au film by nanojoule-energy femtosecond laser pulses as a single-step and scalable technology for realization of plasmonic metasurfaces supporting collective plasmonic re-sponse. Using an adjustable aperture to control and upscale the size of the fabricated nanostructures, nanobumps and nanojets, we demonstrated plasmonic metasurface supporting collective resonances with a moderately high Q-factor (up to 17) and amplitude (up to 45%) within expanded spectral range (1.4–4.5 µm). Vacuum deposition of thin films above the as-fabricated nanostructure arrays was demonstrated to provide fine tuning of the resonance position, also expanding the choice of available materials for realization of plasmonic designs with extended functionality.