Kwon, H.D'Aguanno, GiuseppeAlú, A.2022-06-302022-06-302021-03-09H. Kwon, G. D’Aguanno, and A. Alú, "Optically transparent microwave absorber based on water-based moth-eye structures," Opt. Express 29, 9190-9198 (2021).https://doi.org/10.1364/OE.418220http://hdl.handle.net/11603/25088We propose an approach to realize an optically transparent microwave absorber based on water-based moth-eye metamaterial structures. The absorber is made of a periodic array of properly shaped glass caps infiltrated with distilled water. Analytical calculations and numerical simulations show that the water-based metamaterial absorbs electromagnetic waves over a wide spectral band ranging from 4GHz to well above 120GHz, showing absorption levels close to 100% for incident radiation that ranges from normal to grazing angles, for both TE and TM polarizations. Yet, the structure is optically transparent, offering exciting opportunities in a variety of civil and military applications, such as for camouflage and shielding systems and in energy harvesting structures.9 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)https://creativecommons.org/licenses/by-nc/4.0/Text