Theoretical analysis and simulation of a tunable mid-infrared filter based on Ge2Sb2Te5 (GST) metasurface

Abstract

Based on an all-dielectric metasurface, we propose a tunable high-efficiency optical filter in the mid-infrared (mid-IR) range, which is composed of Ge2Sb2Te5 (GST) nanodisk arrays. By increasing the crystallization of the GST, the proposed reflective optical filter can work effectively in wavelength range of 3.55–6.14 μm. The theoretical analysis demonstrate that the filter function is originating from the excitation of the magnetic Mie resonance. The simulation results show that the proposed filter possesses another advantage of incident angular independence and polarization independence. These results suggest that the proposed all-dielectric metasurface may find great potential applications in optical filter.