Simulation by Molecular Dynamics of Erbium-Activated Silica-Titania Glasses

摘要

Rare-earth doped silicate-based glasses are widely used in teleconnunication technology.A limitation in the performance of active optical devices such as amplifier comes from the rare-earth clustering.Simulation methods give complementary informations to the spectroscopic usual investigations.We present a molecular dy-namics simulation of a SiO_2-TiO_2:Er~3+ system in varying its composition.Different distribution functions have been analyxed in order to have information about the clustering of erbium.To this purpose,The titanium distribution has been studied for concentration 7.8 and 15.7% Ti/(Ti+Si).We have simulated the structure of the system doped with 1 and 2.3 mol%.A calculation fo the crystal field strength for the different kinds of erbium site has been interpreted in the light of the local structure.The important trend of erbium for clustering in our modeled system has been explained by the energetic requirements of the rare-earth.