Enhancement of Full-Color Filtering and Sensing Characteristics Using Metasurface Configuration

We propose two complementary nanoscale metasurface designs, which are specifically tailored for color modulation and refractive index sensing in the visible spectrum. One is an H-shaped metasurface (HSM-1) on a patterned silver (Ag) layer with a nanohole array, which shows stable color spectra tuning across the wavelength range from 415 to 764 nm by adjusting the surrounding refractive index. The average sensitivity is 291.3 nm/RIU. The other is an H-shaped silicon (Si) nanostructure suspended above an Ag mirror with nanogaps (HSM-2). It achieves ultranarrow resonances with a minimum bandwidth of 1.41 nm and a maximum quality (Q) factor of 388.5. For a refractive index sensing application, the maximum sensitivity is 776.9 nm/RIU, and the maximum figure of merit is 531.4. These nanophotonic platforms, with their deep-subwavelength field confinement and nanostructure control, are suitable for applications in optical displays, imaging, biosensing, and integrated nanophotonics.