“…The spectroscopic properties of Tm-doped silicate, fluorophosphate, germanate, and tellurite glasses or crystals have been studied for decades [1][2][3][4][5]. Most studies have been focused on the development of fiber laser systems capable of delivering efficient high-power output at a wavelength of 2 lm because of its applications in the area of remote sensing, medical surgery, environmental sensing, and light sources for efficient mid-IR generation [6][7][8][9].…”