Dual-band selective circular dichroism in mid-infrared chiral metasurfaces
Dual-band selective circular dichroism in mid-infrared chiral metasurfaces
复制标题
DOI：
10.1364/oe.457218
复制
发表时间：
2022-05-23
期刊：
影响因子：
3.8
通讯作者：
Gao, Jie
中科院分区：
文献类型：
--
作者：
Tang, Haotian;Rosenmann, Daniel;Gao, Jie
大多数手性超材料和超表面被设计成在单一波长带内工作，并具有一定的圆二色性（CD）值。本文设计并演示了具有双波长选择性CD的中红外手性超表面吸收材料。手性超表面吸收剂的双带CD选择性和可调性是通过具有两个耦合矩形棒的独特设计实现的。结果表明，通过简单地调整垂直矩形条的宽度和长度等几何参数，可以独立控制和翻转各波段的CD符号。通过研究圆偏振光入射下耦合棒中支持的反键和成键模式的电场和磁场分布，进一步揭示了手性超表面吸收材料中双带CD选择的机理。此外，通过增大超表面单元胞的几何参数，手性共振波长可以持续增加。所展示的结果将有助于未来中红外应用的发展，如手性分子传感、热光伏和光通信。(C)根据Optica开放获取出版协议条款，2022年Optica出版集团
Most chiral metamaterials and metasurfaces are designed to operate in a single wavelength band and with a certain circular dichroism (CD) value. Here, mid-infrared chiral metasurface absorbers with selective CD in dual-wavelength bands are designed and demonstrated. The dual-band CD selectivity and tunability in the chiral metasurface absorbers are enabled by the unique design of a unit cell with two coupled rectangular bars. It is shown that the sign of CD in each wavelength band can be independently controlled and flipped by simply adjusting the geometric parameters, the width and the length, of the vertical rectangular bars. The mechanism of the dual-band CD selection in the chiral metasurface absorber is further revealed by studying the electric field and magnetic field distributions of the antibonding and bonding modes supported in the coupled bars under circularly polarized incident light. Furthermore, the chiral resonance wavelength can be continuously increased by scaling up the geometric parameters of the metasurface unit cell. The demonstrated results will contribute to the advance of future mid-infrared applications such as chiral molecular sensing, thermophotovoltaics, and optical communication. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement