On a causal dispersion model for the optical properties of metals.
On a causal dispersion model for the optical properties of metals.
复制标题
关于金属光学特性的因果色散模型。
作者：
J Orosco;C. Coimbra
一个因果模型，是完全符合的Kramers-Kronig关系（KKRs）用于表征金属的光学响应表现出尖锐的，非洛伦兹带间吸收区域。这个一致的模型也恢复了高斯特性的非晶材料的红外响应中观察到的加宽的峰。本文介绍了一种简化的方法，将KKR复合材料模型最佳拟合到金属带内和带间能量区的介电常数数据上，并应用于11种金属：Ag，Au，Cu，Al，Be，Cr，Ni，Pd，Pt，Ti和W。我们表明，使用这种最佳的程序获得的结果优于定性和定量的那些由以前的非因果关系（KKR非兼容）模型，被广泛用于近似金属的介电常数。比较分析表明，同时增加性能（其特征在于错误目标）和减少基数的参数化，往往产生更有物理意义的解释。这些结果是在不影响模型保真度的尖锐高斯带间字符的区域，表明该模型提供了一个很好的替代以前提出的模型。
A causal model that is fully compliant with the Kramers-Kronig relations (KKRs) is used for characterizing the optical response of metals exhibiting sharp, non-Lorentzian regions of interband absorption. This consistent model also recovers the Gaussian character of the broadened peaks observed in the infrared response of amorphous materials. A reductive procedure for optimal fitting of KKR-compliant composite models to the permittivity data of metals over the intraband and interband energetic regimes is introduced and applied to eleven metals: Ag, Au, Cu, Al, Be, Cr, Ni, Pd, Pt, Ti, and W. We show that results obtained using this optimal procedure outperform-both qualitatively and quantitatively-those obtained by previous non-causal (KKR non-compliant) models that are widely used for approximating the permittivity of metals. A comparative analysis reveals a simultaneous increase in performance (as characterized by the error objective) and a reduction in the cardinality of the parameterization, often yielding more physically meaningful interpretations. These results are obtained without compromising model fidelity in regions of sharp Gaussian interband character, indicating that the proposed model provides an excellent alternative to previously proposed models.