Inverse method for solving coupled-mode theory parameters of two antenna-type resonators exhibiting Fano spectral response

This article presents a deterministic inverse method to get for coupled-mode theory parameters of two antenna-type resonators on the base of their Fano-type spectral response. It relies on a minimal set of target specifications, namely the frequencies of the transmission maximum and minima associated with electromagnetically induced transparency, together with the average radiative loss. These parameters are defined independently of the near-field coupling coefficient, which can be determined a posteriori. Using numerical data from the literature, we have demonstrated the effectiveness of our method for the reverse-engineered design of coupled resonator parameters and obtained good agreement between our analytical model and the results of full 3D numerical simulations. The proposed method opens promising perspectives for the design of large-area aperiodic metasurfaces, enabling wavefront control at sub-wavelength resolution. Beyond design, the analysis provides insight into the physical mechanisms underlying Fano resonances, highlighting the respective roles of radiative interference and non-radiative dipole–dipole coupling. Constructive and destructive interferences have been shown to largely predominate in the case of radiative coupling, while Förster-like resonance predominates in the case of near-field coupling. These results are promising for the design of innovative metasurfaces and will be explored in a subsequent study.