All‐Dielectric Near‐Infrared Metasurface with Field Enhancement and High Q‐Factor Based on Anapole Precise Manipulation

Abstract Anapole resonances with high‐quality factor (Q‐factor) can provide strong local electromagnetic fields for dielectric metasurfaces, combined with unique non‐radiation which can play an important role in sensing, nonlinear optics, and other fields. Perfect anapole mode excitation is still a challenge in the near‐infrared band. In this work, a method is proposed to realize the precise control of electric dipole (ED) and toroidal dipole (TD) by introducing elliptical air holes (EAH) and semi‐elliptical slit (SES), so as to excite the perfect anapole mode. The proposed patterned‐matesurface (Pa‐Meta) is prepared by electron beam lithography (EBL) technology, and combined with the built spectral detection system, it is verified that the method can increase the Q‐factor by 7.84 times (58 to 455). In addition, through the simulation calculation, the electric field enhancement factor | E/E 0 | can be increased by 5.87 times (9.2 to 54). Based on the anapole characteristic of patterned metasurfaces, An analysis of their sensing properties is conducted, revealing a sensitivity of 399.4 nm RIU −1 . This study offers a novel perspective for accurately controlling anapole modes in all‐dielectric metasurfaces, as well as their potential applications in optical sensing and spectroscopy.