Ag nanoparticles enhanced 3.1 μm mid-infrared emission of Er3+/Bi+ co-doped oxyfluoride tellurite glasses

The Er3+/Bi+/Ag nanoparticles (NPs) triple-doped oxyfluoride tellurite glasses were prepared by melt-quenching method, showing an intense 3.1 μm mid-infrared fluorescence emission under 980 nm laser diode pumping. The as-prepared tellurite glass samples exhibit good thermal stability and resistance to crystallization based on X-ray diffraction and differential scanning calorimetry measurements. After an introduction of AgNPs into the tellurite glass matrix, a broadband fluorescence emission at 3.1 μm is detected, in which the full width at half maximum (FWHM) is 181 nm. Moreover, the 3.1 μm fluorescence intensity in this Er3+/Bi+/AgNPs triple-doped glass is enhanced by 42%, compared with a pristine sample, and the corresponding fluorescence lifetime is obtained with a value of 0.53 ms. It is reasonable that there is strong absorption of the incident photons due to the vibration frequency matching between AgNPs and incident photons, it can promote the localized surface plasmon resonance and energy transfer between AgNPs and Er3+ ions, and in turn lead to an enhancement of fluorescence intensity. The above results demonstrate that the as-prepared Er3+/Bi+/AgNPs triple-doped oxyfluoride tellurite glasses possess excellent fluorescence properties and may be a good carrier for mid-infrared fibers and laser gain materials.