基于Kramers-Kronig关系建立金属太赫兹色散模型

发布时间：2018-07-11 11:38

本文选题：太赫兹 + 远红外　；参考：《物理学报》2017年12期

【摘要】：提出了一种基于测量反射率谱、使用Kramers-Kronig(KK)关系建立金属太赫兹色散模型的方法.结合合金铝和合金铜4—40 THz的测量反射率谱,通过反射系数振幅和相位的KK关系,采用高频端指数外推,低频端常数外推的方法,反演金属复折射率.以KK反演的复折射率作为实验值,以拟合复折射率和实验值误差最小为准则,使用遗传优化算法,拟合了合金铝和合金铜的Drude色散参数(等离子频率和碰撞频率).基于优化的Drude模型计算了0.1—40 THz材料的复折射率,与椭偏仪的实测结果符合,验证了模型的准确性.该方法理论与实验相互验证,以测量的复折射率作为实验定标,将远红外频段的色散信息拓展到太赫兹频域,确定了太赫兹频段金属的微观物理参数,提供了太赫兹频段色散和散射机理的研究依据.
[Abstract]:Based on the reflectance spectrum measurement, a method is proposed to establish the terahertz dispersion model of metals by using Kramers-Kronig (KK) relation. Combined with the reflectance spectra of aluminum alloy and copper alloy at 4-40 THz, the complex refractive index of metals was inversed by the method of index extrapolation at high frequency and extrapolation of constant at low frequency by KK relation of reflection coefficient amplitude and phase. Taking the complex refractive index of KK inversion as the experimental value and the minimum error of fitting complex refractive index and experimental value as the criterion, the Drude dispersion parameters (plasma frequency and collision frequency) of aluminum alloy and copper alloy are fitted by genetic optimization algorithm. Based on the optimized Drude model, the complex refractive index of 0.1-40 THz material is calculated, which is in agreement with the measured results of ellipsometer, and the accuracy of the model is verified. The theory of this method is verified by experiments, and the complex refractive index is used as the experimental calibration. The dispersion information in far infrared band is extended to terahertz frequency domain, and the microphysical parameters of metal in terahertz band are determined. The study of dispersion and scattering mechanism in terahertz band is provided.
【作者单位】：西安电子科技大学物理与光电工程学院信息感知技术协同创新中心;中国科学院上海技术物理研究所红外物理国家重点实验室;西安工业大学光电工程学院;
【基金】：国家自然科学基金(批准号:61571355)资助的课题~~
【分类号】：O441;TG113.22

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