Measurement of Complex Dielectric Constant Using Optical Method

This paper describes a method for the determination of complex dielectric constant of an optically absorbing medium. The method involves precise measurement of reflectivity of a p-polarized light at the intensity minimum and the determination of the corresponding pseudo-Brewster angle. The practical usefulness of this method is demonstrated by measuring the complex dielectric constant of Stainless Steel SS304. Using this method, the complex dielectric constant of SS304 has been estimated to be $\hat {\varepsilon }=-8.83-i 13.19$ , which matches well with the values available in the literature. The uncertainty analysis for measurements has also been carried out. The results from the present technique are found to have a good match with other well-established techniques. Furthermore, it has the advantage of being easy to operate and having improved uncertainty.