Infrared emission from holmium doped gallium lanthanum sulphide glass

Infrared emission at 1.2, 1.25, 1.67, 2.0, 2.2, 2.9, 3.9, and 4.9 mu m is measured in holmium (Ho3+) doped gallium lanthanum sulphide (GLS) glass. Branching ratios, radiative quantum efficiencies, and emission cross-sections are calculated from lifetime, absorption, and emission measurements using Judd-Ofelt analysis and the Fuchtbauer-Ladenburg equation. The fluorescence band at 3.9 mu m coincides with an atmospheric transmission window and the fluorescence band at 4.9 mu m overlaps with the fundamental absorption of carbon monoxide, making the glass a potential fibre laser source for remote sensing and gas sensing applications. This is the first time this latter transition has been reported in any holmium doped host. (C) 1999 Elsevier Science B.V. All rights reserved.