Abstract: This paper presents an overview of the history,modifications,characteristics,and applications of two well known dielectric function models--the Forouhi-Bloomer model and the Tauc-Lorentz model--which have been widely used for the extraction and parameterization of optical constants in semiconductors and dielectrics.Based on analysis of their inherent characteristics and comparison via demonstrative examples,deeper and wider usage of the two models is predicted.

Key words: dielectric function models, optical constants, semiconductors