Praseodymium mid-infrared emission in AlF₃-based glass sensitized by ytterbium

Abstract

Broadband emission was obtained over 2.6 to 4.1 μm (Pr 3+ : 1 G 4 → 3 F 4 , 3 F 3 ) in AlF 3 -based glass samples doped with different concentrations of praseodymium and 1 mol% ytterbium using a 976 nm laser pump. An efficient energy transfer process from Yb 3+ : 2 F 5/2 to Pr 3+ : 1 G 4 was analyzed through emission spectra and fluorescence lifetime values. The absorption and emission cross-sections were calculated by Füchtbauer-Ladenburg and McCumber theories and a positive gain can be obtained when P>0.3. To the best of the authors’ knowledge, this work represents the first report of broadband mid-infrared emission of Pr 3+ in an AlF 3 -based glass. The results show that praseodymium doped AlF 3 -based glass sensitized by ytterbium could be a promising candidate for fiber lasers operating in mid-infrared region.