Upconversion channels in Er³⁺:ZBLALiP fluoride glass microspheres

¹ Physics Department, University College Cork, Cork, Ireland
² Photonics Centre, Tyndall National Institute, Prospect Row, Cork, Ireland
³ Department of Applied Physics and Instrumentation, Cork Institute of Technology, Bishopstown, Cork, Ireland
⁴ Laboratoire de Chimie de la Matière Condensée de Paris, ENSCP, 11 rue Pierre et Marie Curie, 75005 Paris, France
⁵ ENSSAT-FOTON (CNRS-UMR 6082) Université de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex, France

Corresponding author: s.nicchormaic@ucc.ie

Received: 29 May 2007
Revised: 21 August 2007
Accepted: 28 August 2007
Published online: 31 October 2007

Abstract

We present results on the realization of a multicolour microspherical glass light source fabricated from the erbium doped fluoride glass ZBLALiP. Whispering gallery mode lasing and upconversion processes give rise to laser and fluorescent emissions at multiple wavelengths from the ultraviolet to the infrared. Thirteen discrete emissions ranging from 320 to 849 nm have been observed in the upconversion spectrum. A Judd-Ofelt analysis was performed to calculate the radiative properties of Er³⁺:ZBLALiP microspheres, including the radiative transition probabilities, the electric dipole strengths, the branching ratios and the radiative lifetimes of the transitions involved. We have also identified the primary processes responsible for the generation of the observed wavelengths and have shown that this material has an improved range of emissions over other erbium doped fluoride glasses.