A Quantitative Model for the Dielectric Tensor of Hyperbolic Metasurfaces

Abstract Hyperbolic metasurfaces (HMS) provide a versatile platform for controlling lightmatter interactions at deep-subwavelength scales. However, theoretically describing their dielectric response remains challenging. Here, we present an inverse dielectric modeling framework for quantitatively retrieving the dielectric tensor of HMS by combining finite element (FEM) simulations with optical transfer matrix calculation. Unlike conventional effective medium theory (EMT), which neglects thickness effects, the proposed alternative dielectric model (ADM) accurately reproduces the polarization-dependent transmission spectra of actual HMS. The retrieved dielectric tensor further enables precise prediction of phonon polariton propagation, including the hyperbolic-to-elliptical wavefront transition and the associated polariton wavelengths, in excellent agreement with full-wave simulations of the actual structure. This work establishes a practical and efficient approach for dielectric tensor retrieval in anisotropic metasurfaces and provides a reliable foundation for the design and optimization of hyperbolic polariton-based nanophotonic devices.