Spectroscopic data of the 1.8, 2.9 and 4.3µm transitions in dysprosium-doped Ga:La:S glass

Abstract

Infrared emission at 1.8, 2.9, and 4.3 µm is measured in dysprosium-doped gallium lanthanum sulfide (Ga:La:S) glass excited at 815 nm. Emission cross sections were calculated by Judd-Ofelt analysis, the Füchtbauer-Ladtenburg equation, and the theory of McCumber. The sigma tau value for the 4.3-µm transition is ~4000 times larger in the Ga:La:S glass than in a dysprosium-doped LiYF4 crystal, which has lased on this transition. The large sigma tau value and the recently reported ability of Ga:La:S glass to be fabricated into fiber form show the potential for an efficient, low-threshold mid-infrared fiber laser. The fluorescence peak at 4.3 µm coincides with the fundamental absorption of atmospheric carbon dioxide, making the glass a potential laser source for gas-sensing applications