Abstract

We numerically investigate two Fano resonances with high Q-factors based on a permittivity-asymmetric metastructure composed of two pea-shaped cylinders. By employing different materials to break the permittivity-asymmetry, the quasi-bound state of the continuum spectrum (BIC) resonance at 982.87 nm is excited, showing the Q-factor as high as 8183.7. The electromagnetic fields and vectors are analyzed by using the finite-difference time-domain (FDTD) method, and the resonance modes are identified as magnetic dipole (MD) responses and MDs by multipole decomposition in Cartesian coordinates, displaying that the light is confined within a pea-shaped cylinder to achieve localized field enhancement. In addition, the sensing performances of the metastructure are evaluated, and an optical refractive index sensor can be obtained with the sensitivity of 152 nm/RIU and maximum figure of merit (FOM) of 832.6. This proposed structure offers a new, to the best of our knowledge, way to achieve Fano resonant excitation on all-dielectric metastructures and can be used in nonlinear optics, biosensing, optical switches, and lasers.

© 2023 Optica Publishing Group

High-Q Fano resonances in all-dielectric metastructures for enhanced optical biosensing applications

Huawei Chen, Xinye Fan, Wenjing Fang, Bingyuan Zhang, Shuangshuang Cao, Qinghe Sun, Dandan Wang, Huijuan Niu, Chuanchuan Li, Xin Wei, Chenglin Bai, and Santosh Kumar
Biomed. Opt. Express 15(1) 294-305 (2024)

Multi-function sensing applications based on high Q-factor multi-Fano resonances in an all-dielectric metastructure

Shuangshuang Cao, Xinye Fan, Wenjing Fang, Mengcheng Du, Qinghe Sun, Huijuan Niu, Chuanchuan Li, Xin Wei, Chenglin Bai, Jifang Tao, Mingxin Li, Baoxi Chen, and Santosh Kumar
Biomed. Opt. Express 15(4) 2406-2418 (2024)

Multiple Fano resonances excitation on all-dielectric nanohole arrays metasurfaces

Lei Yang, ShiLin Yu, Hao Li, and TongGang Zhao
Opt. Express 29(10) 14905-14916 (2021)

All-dielectric metasurface with multiple Fano resonances supporting high-performance refractive index sensing

Chen Zhao, Yiping Huo, Tong Liu, Zuxiong Liao, Congmu Xu, and Tao Zhang
J. Opt. Soc. Am. B 41(1) 36-45 (2024)

Excitation of multiple Fano resonances on all-dielectric nanoparticle arrays

Dandan Wang, Xinye Fan, Wenjing Fang, Huijuan Niu, Jifang Tao, Chuanchuan Li, Xin Wei, Qinghe Sun, Huawei Chen, Hening Zhao, Yingxin Yin, Wenjing Zhang, Chenglin Bai, and Santosh Kumar
Opt. Express 31(6) 10805-10819 (2023)