Investigation of Tm3+/Yb3+ co-doped germanate–tellurite glasses for efficient 2 µm mid-infrared laser materials

Abstract

The Tm3+/Yb3+ co-doped germanate–tellurite glasses with good thermal properties were prepared. Based on the absorption spectra and the Judd–Ofelt theory, the J–O intensity parameters (Ω t ), radiative transition probability (276.78 s− 1), fluorescence lifetime (3.89 ms), absorption and emission cross sections ( $${\sigma _{\text{e}}}$$ = 1.35 × 10− 20 cm2) were calculated. The ~ 2 µm mid-infrared emission resulting from the 3F4→3H6 transition of Tm3+ sensitized by Yb3+ was observed pumped by 980 nm LD. Besides, the energy transfer mechanism between Yb3+ and Tm3+ was thoroughly discussed. The measured ~ 2 µm emission lifetime of Tm3+/Yb3+ co-doped glass can reach as high as 2.38 ms. The above results showed that Tm3+/Yb3+ co-doping glass could be expected to be a promising material to achieve high efficient ~ 2 µm lasing with a 980 nm LD pumping.