Revisiting the experimental dielectric function datasets of gold in accordance with the Brendel-Bormann model

Abstract

As a result of adopting various sample preparation techniques and optical measurement strategies, there are different experimental datasets available for presenting the complex dielectric function of gold. Therefore, evaluating them and selecting the most reliable ones seem essential for the corresponding optical-based designs and applications. The Brendel-Bormann model, one of the most accurate theoretical models for rendering the complex dielectric function of materials, is considered an appropriate criterion for this purpose. Despite the model's computational complexity, MS Excel has been employed as a fast and accessible tool for calculating the model. According to the results, ‘Palik' and ‘Babar' exhibit the most accurate datasets representing the real part of the dielectric function of gold in the short- (<500 nm) and long-wavelength (>500 nm) ranges, respectively. While the proposition reverses for the imaginary part of the dielectric function. This validity owes to using gold samples with the lowest structural and surface imperfections.