Frequency tunable mid-infrared split ring resonators on a phase change material

Meta-surfaces arrays are 2D meta-materials with a periodicity below the diffraction limit that permits to obtain homogeneous layers of resonant effective refractive index. In this work we present an analytical model that describes the electromagnetic behavior of meta-surfaces constituted by split-ring resonators (SRR). SRR resonance frequency can be adjusted by choosing their geometric parameters and the materials they are made of. Their deposition on a phase change material enables an optical modulation of resonance peak during the phase transition. We demonstrate a mid-infrared tunable SRR meta-surface using Vanadium dioxide (VO₂) as phase change material deposited on III-V semiconductors by low temperature pulsed laser ablation technique. The presented measurements exhibit a maximum of 100 cm⁻¹ resonance shift. This result is very promising for the conception of monolithic, robust, compact, frequency tunable III-V based devices in the mid-infrared.