Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Photonics Initiative, Advanced Science Research Center and Graduate Center, City University of New York, New York, New York 10075, United States.
Nano Lett. 2021 Jan 27;21(2):973-979. doi: 10.1021/acs.nanolett.0c03957. Epub 2020 Dec 29.
Subwavelength nanostructures with tunable compositions and geometries show favorable optical functionalities for the implementation of nanophotonic systems. Precise and versatile control of structural configurations on solid substrates is essential for their applications in on-chip devices. Here, we report all-solid-phase reconfigurable chiral nanostructures with silicon nanoparticles and nanowires as the building blocks in which the configuration and chiroptical response can be tailored on-demand by dynamic manipulation of the silicon nanoparticle. We reveal that the optical chirality originates from the handedness-dependent coupling between optical resonances of the silicon nanoparticle and the silicon nanowire via numerical simulations and coupled-mode theory analysis. Furthermore, the coexisting electric and magnetic resonances support strong enhancement of optical near-field chirality, which enables label-free enantiodiscrimination of biomolecules in single nanostructures. Our results not only provide insight into the design of functional high-index materials but also bring new strategies to develop adaptive devices for photonic and electronic applications.
具有可调组成和几何形状的亚波长纳米结构为实现纳米光子系统提供了有利的光学功能。在固体衬底上精确和多功能地控制结构配置对于它们在片上器件中的应用至关重要。在这里，我们报告了全固态可重构手性纳米结构，其构建块为硅纳米颗粒和纳米线，通过动态操纵硅纳米颗粒，可按需调整其结构和手性响应。我们通过数值模拟和耦合模理论分析揭示了光学手性源于硅纳米颗粒和硅纳米线之间的光共振的手性相关耦合。此外，共存的电和磁共振支持光学近场手性的强烈增强，这使得能够在单个纳米结构中对生物分子进行无标记的对映体选择性检测。我们的结果不仅为功能高折射率材料的设计提供了深入的了解，而且为开发用于光子和电子应用的自适应器件带来了新的策略。
