基于氧化铟锡的风扇型中红外手性超材料及其圆二向色性

Fan-shaped mid-infrared chiral metamaterials based on indium tin oxide and their circular dichroism

本文设计了一种中红外波段手性超材料以克服传统中红外激光偏振态调控所使用的控制元件体积大、成本高等不足。利用中红外等离激元材料氧化铟锡(ITO)设计风扇型手性结构,并研究了该结构在中红外波段的圆二向色性(CD)。通过改变扇叶层填充材料、扇叶厚度、扇叶大小、扇叶数量以及扇叶的材料,讨论结构的CD变化情况。模拟结果表明:当填充材料为硅、扇叶为6片时,选取合适的扇叶厚度和大小,在5.3μm附近获得最强的CD信号,为0.052。此外,与贵金属银、金相比,由ITO构成的结构展现出良好的宽带圆二向色性,这为中红外波段宽带偏振态调控器件的设计提供了新的思路。

A mid-infrared chiral metamaterial was designed to overcome the problems of large volume and high cost of traditional mid-infrared laser polarization state controls,The fan-shaped chiral structure material made of Indium Tin Oxide(ITO)was designed and its Circular Dichroism(CD)characteristics in the mid-infrared band were studied.The CD variation characteristics of the structure were discussed by changing the filling material,the thickness,the size,the number,and the material of fan blades.The simulation results show that when the filling material is silicon and the number of fan blade is six,the strongest CD signal of 0.052 is obtained near the wavelength of 5.3μm by selecting the appropriate fan thickness and size.Moreover,compared with the silver and gold,the structure made of ITO exhibits broadband circular dichroism,which provides a new idea for the design of broadband polarization-state control devices in the midinfrared band.