The chemical reactions and diffusion processes at the interface of a metal with oxides and nitrides are a critical issue in the production of metal-dielectric optical filters. The optical properties of these filters depend on the quality of the interfaces between the metal layer and the adjacent dielectric layers. The chemical and physical processes occurring at the silver-dielectric interface are studied by means of ellipsometry and XPS analysis and comprise the subject of the present work. (C) 2003 Elsevier B.V. All rights reserved.