Aerosol-gel preparation of optically active layers in the system Er/SiO2-TiO2

Er-doped silica-titania multilayer coatings have been successfully deposite d using an original sol-gel deposition technique: the Aerosol-gel process. This study is the first step toward Aerosol-gel preparation of active plana r wave guides. In this paper, we report on the physical, chemical, optical, microstructural and spectroscopic properties of the multilayer coatings. A new optically active crystalline phase, Er2Ti2O7 (ETO), has been identifie d. This study shows that, depending on the experimental conditions (titaniu m and erbium content, heat treatment temperature), ETO can be obtained in t he form of nanocrystallites dispersed in a transparent amorphous matrix. (C ) 2000 Elsevier Science S.A. All rights reserved.