Generally optical absorbers exploit a relatively thick metallic plate to ensure zero transmission via the structure. Also some parts of absorbers are modeled by circuit elements helping transmission line theory. There are several works in THz spectrum that consider bottom gold surface as "Short Circuit", assuming relatively thick golden plate compared to penetration depth. The question here is that how to model this metallic surface versus both thickness and penetration depth. In a more simple view, I am curious about modeling this palate when thickness is smaller than penetration's depth.