Refractive Index Sensing Based on Metasurface Coupled Surface Wave

Sensitivity is the most important character of metasurface-based sensors in effective substance detection and comprehensive bio-interaction studies. Demonstrating our experimental verification, successful excitation and propagation of surface waves (SWs) occur on a metasurface, benefitting from both long-range transmission and strong confinement. Integrated sensing capabilities are enabled by the proposed metasurface, which supports SWs. Notable is the refractive sensing capability, which extends up to 215.5°/RIU. Experimental results reveal maximum phase changes of 91.1°, 101.8°, and 126.4°, respectively, with the coverage of 5 μm thickness of polyimide, quartz, and silicon nitride layers within the THz band.