Stable Multi-Wavelength Resonant Metal-dielectric Hybrid Nanostructure in the Infrared Range

Abstract

Plasmonic nanostructures typically exhibit shifts in their resonant wavelength in response to changes in the refractive index of the surrounding medium. This limits their applications in scenarios requiring stable optical resonances. Here we present a metallic-dielectric hybrid metasurface that exhibits stable multi-wavelength resonance even if the refractive index of its surrounding varies. To quantitatively evaluate the stability of the optical response, we introduce a stability factor FS = Δn/Δλ. Here, Δn and Δλ represent variation of refractive index and shift of the resonant wavelength, respectively. A larger factor indicates better stability. The factor reaches 5 RIU/μm when silicon is employed as the central dielectric and increases to 33.3 RIU/μm when Bi 2 Te3 is utilized instead. The proposed innovative structure has potential applications in the development of substrates for in-vitro cell cultivation. Under broadband light illumination, it stably absorbs light at specific wavelengths, creating a consistent optical microenvironment leading to cell growth. It can find potential applications in precise control of various cellular processes, including metabolism and differentiation. It potentially brings a paradigm shift in the fields of cell based research and regenerative medicine, opening up new avenues for scientific exploration and therapeutic advancements.