Upconversion emission in Er(3+)-doped lead niobium germanate thin-film glasses produced by pulsed laser deposition

5 pages, 6 figures.-- PACS nrs.: 78.20.-e, 78.47.Cd, 78.55.Qr, 78.66.Jg.-- Printed version published on Nov 2008.Thin films of Er(3+)-doped lead–niobium germanate have been produced by pulsed laser deposition from Er(3+)-doped 25PbO2–25Nb2O5–50GeO2 (mol%) transparent glasses with an Er content in the range 0.5–3 wt%. The room-temperature infrared to visible upconversion properties of these thin films have been investigated under 800-nm laser excitation. An energy transfer upconversion mechanism has been identified to be responsible for the population of the 4S3/2:2H11/2 excited level, from which an intense green emission occurs. A rate equation analysis supports the proposed mechanism.We wish to thank the Spanish Ministry of Educación y Ciencia (MAT 2004-6868, MAT 2005-06508-C02, and MAT 2007-63319) for financial support.Peer reviewe