Hybrid all-dielectric phase-change metasurfaces for tunable waveplate

Metasurfaces have attracted immense interest across various scientific disciplines due to their ability to manipulate light wave parameters with numerous functionalities. However, these functionalities have historically been static, lacking the capability for dynamic, real-time control. In this study, we introduce a highly efficient, tunable waveplate by incorporating a thin layer of the phase change material Sb2Se3 into a silicon all-dielectric metasurface. This structure demonstrates the ability to transition from a half-waveplate to a quarter-waveplate as Sb2Se3 shifts from an amorphous to a crystalline state at the telecom wavelength of 1.55 μm. Remarkably, it maintains consistent performance across a range of rotation angles. In addition, we have performed comprehensive electro-thermal simulations to validate the phase change process, confirming the practical feasibility of this technology. This tunable metasurface represents a significant advancement in adaptive photonics, offering customizable and sophisticated functionalities.