Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee37235, United States.
Interdisciplinary Materials Science, Vanderbilt University, Nashville, Tennessee37235, United States.
Nano Lett. 2022 Oct 26;22(20):8060-8067. doi: 10.1021/acs.nanolett.2c01919. Epub 2022 Oct 10.
Dielectric metasurfaces governed by bound states in the continuum (BIC) are actively investigated for achieving high-quality factors and strong electromagnetic field enhancements. Traditional approaches reported for tuning the performance of quasi-BIC metasurfaces include tuning the resonator size, period, and structure symmetry. Here we propose and experimentally demonstrate an alternative approach through engineering slots within a zigzag array of elliptical silicon resonators. Through analytical theory, three-dimensional electromagnetic modeling, and infrared spectroscopy, we systematically investigate the spectral responses and field distributions of the slotted metasurface in the mid-IR. Our results show that by introducing slots, the electric field intensity enhancement near the apex and the quality factor of the quasi-BIC resonance are increased by a factor of 2.1 and 3.3, respectively, in comparison to the metasurface without slots. Furthermore, the slotted metasurface also provides extra regions of electromagnetic enhancement and confinement, which holds enormous potential in particle trapping, sensing, and emission enhancement.
受连续束缚态 (BIC) 控制的介电超表面在实现高品质因子和强电磁场增强方面受到了积极的研究。为了调整类 BIC 超表面的性能，传统的方法包括调整谐振器的尺寸、周期和结构对称性。在这里，我们提出并通过实验证明了一种通过在锯齿形椭圆硅谐振器阵列中引入狭缝的替代方法。通过解析理论、三维电磁建模和红外光谱学，我们系统地研究了中红外波段开槽超表面的光谱响应和场分布。我们的结果表明，与没有狭缝的超表面相比，通过引入狭缝，在顶角附近的电场强度增强和类 BIC 共振的品质因子分别提高了 2.1 倍和 3.3 倍。此外，开槽超表面还提供了额外的电磁增强和限制区域，这在粒子俘获、传感和发射增强方面具有巨大的潜力。
