Mid-Infrared Wavelength-Selective Absorbing Metasurfaces Based on Highly-doped Silicon Gratings

We experimentally demonstrate wavelength-selective metasurfaces operating in the mid-infrared spectral range extending from 1000 to 25000 nm. Resonant peaks are observed in the 13000–17000 nm range. The metasurface consists of micrometer-scale one dimensional periodic gratings made of highly-doped silicon using conventional ultra-violet lithography, taking advantage of its plasmonic behavior in the infrared. Simulations results supports understanding the effects of key parameters including the doping concentration and the gratings period.