Sun Kaili, Sun Min, Cai Yangjian, Levy Uriel, Han Zhanghua
Shandong Provincial Key Laboratory of Optics and Photonic Devices, Center of Light Manipulation and Applications, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
Department of Applied Physics, and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, Israel.
Nanophotonics. 2022 Aug 9;11(18):4221-4229. doi: 10.1515/nanoph-2022-0311. eCollection 2022 Sep.
Strong light-matter coupling is of much interest for both fundamental research and technological applications. The recently studied bound state in the continuum (BIC) phenomenon in photonics with controlled radiation loss rate significantly facilitates the realization of the strong coupling effect. In this work, we report the experimental observation of room temperature strong coupling between quasi-BIC resonances supported by a zigzag metasurface array of germanium elliptical disks and the vibrational resonance of polymethyl methacrylate (PMMA) molecules in the mid-infrared. Based on the approach of tuning the quasi-BIC resonance by changing the thickness of the coated PMMA layer, we can easily observe the strong coupling phenomenon, manifested by significant spectral splitting and typical anti-crossing behaviors in the transmission spectrum, with the spectral distance between the two hybrid photon-vibration resonances significantly larger than the bandwidth of both the quasi-BIC resonance and the PMMA absorption line. Our results demonstrate that the use of quasi-BIC resonance in all-dielectric nanostructures provides an effective and convenient approach for the realization of strong coupling effect.
强光与物质的耦合在基础研究和技术应用方面都备受关注。最近在光子学中研究的具有可控辐射损耗率的连续域束缚态（BIC）现象极大地推动了强耦合效应的实现。在这项工作中，我们报告了在室温下，由锗椭圆盘的之字形超表面阵列支持的准BIC共振与聚甲基丙烯酸甲酯（PMMA）分子在中红外波段的振动共振之间的强耦合实验观测结果。基于通过改变涂覆的PMMA层厚度来调谐准BIC共振的方法，我们能够轻松观测到强耦合现象，其在透射光谱中表现为显著的光谱分裂和典型的反交叉行为，两个混合光子 - 振动共振之间的光谱距离明显大于准BIC共振和PMMA吸收线的带宽。我们的结果表明，在全介质纳米结构中使用准BIC共振为实现强耦合效应提供了一种有效且便捷的方法。
