Jin Rong, Huang Lujun, Zhou Chaobiao, Guo Jiaoyang, Fu Zhenchu, Chen Jian, Wang Jian, Li Xin, Yu Feilong, Chen Jin, Zhao Zengyue, Chen Xiaoshuang, Lu Wei, Li Guanhai
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083, China.
Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1 SubLane Xiangshan, Hangzhou 310024, China.
Nano Lett. 2023 Oct 11;23(19):9105-9113. doi: 10.1021/acs.nanolett.3c02958. Epub 2023 Sep 11.
Achieving perfect absorption in few-layer two-dimensional (2D) materials plays a crucial role in applications such as optoelectronics and sensing. However, the underlying mechanisms of all reported works imply a strongly inherent dependence of the central wavelength on the structural parameters. Here, we propose a structure-parameter-deviation immune method for achieving perfect absorption at any desired wavelength by harnessing the toroidal dipole-bound state in the continuum (TD BIC). We experimentally demonstrate the versatile design with a monolayer-graphene-loaded compound grating structure. Such a TD BIC built upon the TE mode allows for the transition from BIC to quasi-BIC without breaking the structural symmetry, enabling the stable resonance wavelength while tailoring the quality factors via variation of the gap distance. Comparison with traditional literature further reveals the superiority of our method in realizing highly robust perfect absorption, with a wavelength stability ratio of >15. Remarkably, this approach can be straightforwardly applied to other 2D materials.
在光电子学和传感等应用中，在少层二维（2D）材料中实现完美吸收起着至关重要的作用。然而，所有已报道工作的潜在机制表明，中心波长对结构参数存在强烈的固有依赖性。在此，我们提出一种结构参数偏差免疫方法，通过利用连续统中的环形偶极束缚态（TD BIC）在任何所需波长实现完美吸收。我们通过单层石墨烯负载复合光栅结构对这种通用设计进行了实验验证。基于TE模式构建的这种TD BIC允许在不破坏结构对称性的情况下从BIC过渡到准BIC，从而在通过改变间隙距离调整品质因数的同时实现稳定的共振波长。与传统文献的比较进一步揭示了我们的方法在实现高度稳健的完美吸收方面的优越性，波长稳定率>15。值得注意的是，这种方法可以直接应用于其他二维材料。
