Calculation of the optical constants of a thin layer upon a transparent substrate from the reflection spectrum using a genetic algorithm

A genetic algorithm (GA) is proposed for the calculation of the optical constants of a thin layer upon a thick finite transparent substrate only from the reflection spectrum into the visible and near infrared regions. A particular interest of this method is that it finds the roots fast and very accurately using global minimum. The obtained results using the GA method give spectral dependence of refractive index and film thickness for two reference samples with an error of 0.1%. (C) 2004 Elsevier B.V. All rights reserved.