Effective enhancement on mid-infrared fluorescence emission of Ho3+/Yb3+ doped tellurite glass introduced Ag nanoparticles

In this paper, Ho3+, Yb3+ and metal Ag nanoparticles (NPs) tri-doped tellurite glass were synthesized by melt quenching. Combining X-ray diffraction, Raman spectroscopy, and Differential thermal analysis tests, multiple structural units were found in the synthetic glass samples which provided the possibility to achieve high concentration and uniform doping of rare earth ions without degrading the glass forming ability and thermal stability. The fluorescence emission of glasses at 2 μm, 3.9 μm, and 4.1 μm were focused on, as a consequence, the Ho3+/Yb3+/AgNPs tri-doped tellurite glass achieved strong emission at 2 μm, 3.9 μm and 4.1 μm, and the full width at half maximum (FWHM) at 4.1 μm is 316 nm under the 980 nm LD excitation, which realized broadband fluorescence emission. In addition, the fluorescence lifetimes of the glass at 2 μm, 3.9 μm and 4.1 μm are 4.79 ms, 3.81 ms and 4.28 ms meaning the lower laser oscillation threshold the glass holds. It is particularly noteworthy that the emission intensity had been greatly improved about 30% at 2 μm and 27% at 3.9 μm and 4.1 μm with the introduction of AgCl into the matrix, respectively, which was mainly effected by local surface plasmon resonance (LSPR) of AgNPs and the energy transfer between Ag species and Ho3+, whereas the content of AgCl must be strictly controlled to prevent the concentration quenching to decrease the emission intensity. The obtained results demonstrate that Ho3+/Yb3+/AgNPs tri-doped tellurite glass possesses an ideal application prospect on mid-infrared fiber and laser materials.