Rapid direct laser writing of controllable plasmonic nanoparticles into polarization-sensitive metasurfaces

Plasmonic nanostructures, characterized by strong light absorption and scattering, have attracted significant interest for applications in photonic devices, metasurfaces, and biosensors. However, conventional fabrication methods rely heavily on photolithography or templating, which limits their scalability and efficiency while increasing process complexity and costs. In this work, we propose a femtosecond laser-induced localized dewetting strategy to fabricate nanoparticle-insulator-metal (NIM) metasurfaces with vibrant structural colors. The approach utilizes precisely controlled laser fluence to induce localized photothermal heating of semi-continuous Au films, driving a controllable dewetting process. We demonstrate that the elongation direction of the resulting Au nanostructures is oriented perpendicular to the laser polarization, enabling tunable and polarization-sensitive optical resonances. By leveraging gap surface plasmon resonances (GSPR), the NIM-configured metasurfaces exhibit brilliant plasmonic colors spanning the visible spectrum-from yellow to green and red-as laser power increases. This high-efficiency (up to 0.2 mm/s) and versatile patterning method demonstrates significant potential for high-resolution imaging, anti-counterfeiting, information storage, and optical multiplexing.