Dynamical characteristics of ultrashort terahertz pulse in metamaterials
Dynamical characteristics of ultrashort terahertz pulse in metamaterials
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DOI：
10.1088/1612-202x/ac59bc
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发表时间：
2022-03
影响因子：
1.7
通讯作者：
Zhenqing Zhang;F. Deng;Feng Wu;Chengjie Zhu
中科院分区：
文献类型：
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作者：
Zhenqing Zhang;F. Deng;Feng Wu;Chengjie Zhu
在稳态近似下，我们发展了一种含时的理论方法来研究超短太赫兹脉冲与超材料之间的相互作用。利用光导硅，我们证明了系统色散通过经典干涉效应从反常变为正常。结果，太赫兹脉冲以亚光速/超光速群速度传播通过材料。结果表明，利用耦合波方程的稳态解来预测太赫兹脉冲的传输特性是不准确的，高阶色散项在太赫兹脉冲的传输特性中起着重要作用，它导致了脉冲形状的变形和位置相关的群速度修正.该理论方法对描述太赫兹脉冲在超材料中的传输特性是必要的，有助于理解电磁感应透明超材料中量子干涉的本质。
We develop a time-dependent theoretical approach to study the interaction between the ultrashort terahertz pulse and the metamaterials beyond the steady-state approximation. By using photoconductive silicon, we show that the system dispersion is changed from abnormal to normal via the classical interference effect. As a result, the terahertz pulse propagates through the material with subluminal/superluminal group velocity. We show that it is not accurate to predict the propagation characteristics of the terahertz pulses by using the steady-state solution of coupled wave equations, and the high-order dispersion terms take a significant role which attributes to the pulse shape deformation and the position-dependent group velocity modification. The theoretical approach presented here is essential of describing the propagation properties of the terahertz pulse in metamaterials and is helpful to understand the nature of quantum interference in electromagnetically induced transparency metamaterial.