Reconfigurable Ultraviolet and High-Energy Visible Dielectric Metamaterials

Abstract

Photonic materials with tuneable and switchable ultraviolet (UV) to high-energy-visible (HEV) optical properties would benefit applications in sensing, high-density optical memory, beam-steering, adaptive optics and light modulation. Here, for the first time, we demonstrate a non-volatile switchable dielectric metamaterial operating in the UV-HEV spectral range. Nano-grating metamaterials in a layered composite of low-loss ZnS/SiO2 and the chalcogenide phase-change medium germanium antimony telluride (Ge2Sb2Te5) exhibit reflection resonances at UV-HEV wavelengths that are substantially modified by light-induced (amorphous-crystalline) phase transitions in the chalcogenide layer. Despite the presence of the lossy GST, resonance quality factors up to Q~15 are ensured by the transparency (low losses) of ZnS/SiO2 in the UV-HEV spectral range and values of Q increase as the refractive index of Ge2Sb2Te5 decreases, upon crystallization. Notably however, this switching leaves resonance spectral positions unchanged.

A High‐Index Ge2Sb2Te5‐Based Fabry–Perot Cavity and Its Application for Third‐Harmonic Generation

“…Nevertheless, the integration of graphene layer with large area device can be hard due to its complex nanofabrication processes. In addition, the efficient THG were demonstrated using silicon photonic crystals and silicon metasurfaces …”

Actively Tunable Metalens Array Based on Patterned Phase Change Materials

“…When the GST is tuned between two states, the corresponding permittivity will be changed simultaneously, which can be used to realize active control. Due to its remarkable tuning abilities such as high stability and fast switch speed [29,30], GST has been applied in many novel tunable nano-photonic devices such as multi-wavelength duplex metalens, dipole-quadrupole (DQ) Fano resonance (FR) induced lateral force, beam steering, filter, color control, and ultraviolet/high-energy-visible resonances by combining with metasurfaces [20,[31][32][33][34][35][36], which has proved to be the great potential of GST. Nevertheless, the research for tunable metalens array using phase change materials has not been explored yet.…”

Tunable metasurfaces for visible and SWIR applications

“…Reproduced with permission from ©2016, American Chemical Society. d UV light-tunable meta-atom made of GST sandwiched by ZnS/SiO 2 layers [76]. Reproduced with permission from ©2019, American Chemical Society overcome.…”

“…Gholipour et al demonstrated an optically-tunable metasurface, based on a patterned GST heterostrutcture with ZnS/SiO2 (Fig. 5d), showing tuning capability for ultraviolet (UV) and visible spectra [76]. GST shows a significantly low refractive index at the UV spectrum, as low as 1.07 at 245 nm in the crystalline phase.…”