Radiation trapping in selected Er³⁺ doped chalcogenide glasses and the extraction of the nonradiative lifetime

Abstract

Radiation trapping (RT) is a phenomenon wherein photons are emitted, absorbed and re-emitted many times before they leave the volume of the material. Trivalent Er³⁺ ions are particularly prone to RT because there is a whole set of strongly overlapping emission and absorption bands including  ⁴I_13/2−⁴I_15/2 and ⁴I_11/2−⁴I_15/2 bands. The effect of RT on the PL decay time was investigated experimentally in this work in a variety of Er³⁺-doped GeGaS, GeGaSe, GaLaS(O) glasses. Sample geometry (powders, plates, disks, cylinders) and size were varied and the samples were also immersed in glycol, a liquid with high refractive index. PL decay times were measured and compared with the Judd-Ofelt results. A simple model of RT was developed and applied to the above mentioned bands. By comparing model conclusions with experimental data for different sample sizes, we were able to separate the direct relaxation of the ⁴I_11/2 state to ground ⁴I_15/2 state and relaxation via the intermediate ⁴I_13/2 state; and hence obtain an approximate nonradiative lifetime.

More information

Identifiers

ORCID for Christopher Craig: orcid.org/0000-0001-6919-4294

ORCID for Daniel Hewak: orcid.org/0000-0002-2093-5773

Catalogue record

Export record

Altmetrics