Spectroscopy and frequency upconversion of Er3+ ions in lead niobium germanate glasses

In this work we report the optical properties and upconversion luminescence of Er3+ ions in lead-niobium-germanate glass (GeO2-PbO-Nb2O5) suitable for use in optical waveguide devices. The optical properties of Er3+ ions have been established in terms of absorption and emission spectra and lifetime measurements in the visible and infrared regions. The 1.5 mum emission cross-section has been determined from the line shape of the emission spectrum and the calculated emission probability for the I-4(13/2) level. Upconversion emissions at 529, 548, and 653 nm have been obtained under infrared excitation at 803 nm in the I-4(9/2) level and compared with those obtained under one photon excitation. Pumping power measurements were also carried out. The possible excitation mechanisms responsible for this upconversion luminescence are discussed. (C) 2003 Elsevier B.V. All rights reserved.