We report a detailed comparative investigation of resonance behaviors and sensing capability of gold U-shape spilt-ring resonator (U-SRR) and fourfold rotated SRR (U4-SRR) metasurfaces in near- and middle-infrared (IR) range. All the resonant modes of the U4-SRR metasurfaces occur at longer wavelengths compared to the U-SRR metasurfaces with the same U size. Stronger field intensities are observed in all the three resonance modes of the U4-SRR metasurfaces and the intensity in the fundamental magnetic (m ₀) mode is almost three times of that of U-SRR metasurface under unpolarized incidence. All the three peak resonance wavelengths shift to longer wavelengths and the sensitivity increases with the increase of U size. A sensitivity of 642 nm RIU⁻¹ is obtained in the U4-SRR metasurface for unpolarized incidence. This provides an excellent candidate for high performance sensing in the near- and mid-IR regions without polarization concern.

我们报告了详细的比较研究的共振行为和感应能力的金U形喷溅环共振器（U-SRR）和四倍旋转的SRR（U4-SRR）元表面在近红外和中红外（IR）范围内。与具有相同U尺寸的U-SRR超颖表面相比，U4-SRR超颖表面的所有共振模式都在更长的波长处发生。在U4-SRR超表面的所有三个共振模式下都观察到了更强的场强，在无极化入射下，基本磁（m ₀）模式的强度几乎是U-SRR超表面的三倍。所有三个峰值共振波长都移至更长的波长，并且灵敏度随着U尺寸的增加而增加。灵敏度为642 nm RIU ^-1在U4-SRR超颖表面获得非极化入射。这为近红外和中红外区域的高性能传感提供了极好的选择，而无需考虑偏振问题。