2 μm emission performance in Tm3+/Er3+ codoped silicate glasses under 800 nm and 980 nm excitation

In this paper, mid-infrared 2 μm emission properties and energy transfer mechanism were investigated in Er3+/Tm3+ co-doped silicate glasses with optimized extra-low hydroxyl content ∂OH- (0.73 cm−1). The intensity parameters Ωt (t = 2, 4, 6) were calculated from the measured absorption spectra based on the Judd-Ofelt theory. The energy transfer efficiency from the Er3+:4I13/2 level to the Tm3+:3F4 level was calculated and reached up to 91.2% under 980 nm LD pumps and quantum efficiency is 63%. Meanwhile, the 1.85 μm band stimulated absorption and emission cross-sections of Tm3+:3F4 → 3H6 transitions were also obtained and analyzed. In addition, the measured ΔT (evaluate the glass forming ability) is as high as 297 °C, which shows that the silicate glass (SBET) possess good thermal stability. Hence, all of the present investigations indicate that the Er3+/Tm3+ co-doped silicate glasses have potential applications in 2 μm laser materials and may provide beneficial guide for investigation of population behaviors of Tm3+ ions at 2 μm emissions.