Polarizing gap plasmon metasurfaces implemented by highly-ordered Laser Induced Periodic Surface Structures

We present a method for the realization of gap plasmons polarizing metasurface plates operating in reflection at IR and mid-IR via laser structuring, i.e., laser induced periodic surface structures formed on nanometer-thick metallic films. The method produces a corrugated layer with sinusoidal shaped, periodic, thin, metallic nanowires. Following the laser treatment, the nanowires are back-plated by a grounded dielectric layer resulting in a metal-insulator-metal type metasurface. Fourier-Transform Infrared spectroscopy measurements show that the fabrication approach produces metasurfaces with very well-defined, tunable resonances and polarization sensitive resonant absorption response in the near-IR and mid-IR.