Spectroscopic ellipsometry investigation of azo dye and azo dye doped polymer

Abstract

The optical constants of azo dye (Methyl Red (MR)) and azo dye doped polymer (ADP) (Polymethylmethacrylate (PMMA)) MR/PMMA have been investigated using Variable Angle Spectroscopic Ellipsometry (VASE). Pure MR was modeled using Lorentz formula with three oscillators. A Bruggmann effective medium approximation layer was employed with three constituents (MR, PMMA and void) to represent the thin film of MR/PMMA. The optical constants of MR/PMMA were determined at various MR concentrations. The results reveal that the optical constants of the blend system are a linear interpolation of the two constituents. Average optical constants were determined using multiple sample analysis.