Deposition of profiled optical coatings by masking techniques: A study in the framework of the linear system theory

Fabrication of a coated graded reflectance mirror (GRM) is based on a multilayer design where one or more layers have a radially variable thickness. We describe and experimentally validate a method that can be used to predict the shape of a profiled layer deposited by masking techniques. Deposition by masking techniques is modelled in the framework of the linear system theory. We also suggest an experimental procedure for estimating the Green function that rules particle gas diffusion, and we apply it to the case of RF-sputtering deposition of ZnSe monolayers on BK7 glass. Comparison of predicted and measured reflectivity profiles at lambda =1.064 mu m confirms the model validity.