Highly Reflective, Low-Loss, Homogenized Fishnet Metasurfaces at Terahertz: Design and Experiment

A metasurface based on a fishnet-like unit cell is designed, realized, and measured at terahertz frequencies through time-domain spectroscopy in reflection mode. While most of fishnet-like metasurfaces are designed in the resonant regime (i.e. with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pλ,\ p</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</tex> , being the period and the free-space wavelength), the proposed one is designed in the homogenized regime (i.e. with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pλ</tex> ). Experimental results show that the proposed metasurface exhibits very high reflectivity, which makes it particularly attractive for the design of high-gain Fabry–Perot cavity leaky-wave antennas.