Experimental verification of total absorption by a low-loss thin dielectric layer

摘要

This work presents an experimental demonstration of total absorption by a metal-dielectric meta-surface. Following a theoretical proposal [Diaz-Rubio et al., Phys. Rev. B 89, 245123 (2014)], we have designed and fabricated a metasurface consisting of a low absorbing dielectric layer (made of FR4) placed on top of a metallic surface patterned with a square array of coaxial cavities. For p-polarized waves, a low frequency peak with perfect absorption is observed. The behavior of this peak has been experimentally characterized for different dielectric layer thicknesses, coaxial cavity lengths, and angles of incidence. The experimental results are in excellent agreement with numerical simulation and corroborate the theoretical predictions.