Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.
Nano Lett. 2022 Oct 26;22(20):8181-8188. doi: 10.1021/acs.nanolett.2c02661. Epub 2022 Oct 6.
Chiral plasmonic nanostructures have facilitated a promising method for manipulating the polarization state of light. While a precise structural modification at the nanometer-scale-level could offer chiroptic responses at various wavelength ranges, a system that allows fast response control of a given structure has been required. In this study, we constructed uniformly arranged chiral gold helicoids with cobalt thin-film deposition that exhibited a strong chiroptic response with magnetic controllability. Tunable circular dichroism (CD) values from 0.9° to 1.5° at 550 nm wavelength were achieved by reversing the magnetic field direction. In addition, a magnetic circular dichroism (MCD) study revealed that the gap structure and size-related surface plasmon resonance induced MCD peaks. We demonstrated the transmitted color modulation, where the color dynamically changed from green-to-red, by controlling the field strength and polarizer axis. We believe current work broadens our understanding of magnetoplasmonic nanostructure and expands its potential applicability in optoelectronics or optical-communications.
手性等离子体纳米结构为操控光的偏振态提供了一种很有前途的方法。虽然在纳米级水平上进行精确的结构修饰可以在各种波长范围内提供手性响应，但需要一种能够快速控制给定结构的系统。在这项研究中，我们构建了具有钴薄膜沉积的均匀排列的手性金螺旋体，其表现出具有磁可控性的强手性响应。通过反转磁场方向，在 550nm 波长处实现了可调谐的圆二色性（CD）值从 0.9°到 1.5°。此外，磁圆二色性（MCD）研究表明，间隙结构和与尺寸相关的表面等离激元共振诱导了 MCD 峰。我们通过控制场强和偏振器轴演示了透射颜色调制，其中颜色从绿色动态变为红色。我们相信目前的工作拓宽了对手磁等离子体纳米结构的理解，并扩展了其在光电或光通信中的潜在适用性。
