Tuning the high reflectance Goos-Hänchen shift based on quasi-bound states in the continuum through vanadium dioxide material asymmetric metasurface

To dynamically tune the high-reflectance Goos and Hänchen (GH) shift, a vanadium dioxide metasurface is proposed in this paper, whose material asymmetry parameter can be tuned by the ambient temperature. The material symmetry and geometric symmetry of the metasurface are broken by controlling the material asymmetry parameter γ and incident angle θ, and three symmetry-protected quasi-bound states in the continuum (QBICs) resonances with high-quality factors are excited. Based on the electric/magnetic field vector and multipole decomposition, the three QBIC resonances are excited due to the magnetic quadrupole. The QBIC resonances are applied to dynamically tune the high-reflectance GH shift, and the influence laws of γ and θ on the high-reflectance GH shift are analyzed.