Preparation and performance of Ho3+/Yb3+ co-doped fluorosilicate-emitting broadband near-infrared glasses

In this study, Ho3+/Yb3+ co-doped near-infrared fluorosilicate glass was melting with different concentrations of rare earth ions using a high-temperature melting method. Under 980 nmLD excitation, the Ho3+/Yb3+ co-doped fluorosilicate glass emits a near-infrared radiation of about 2.0 mu m. The upconversion fluorescence spectrum reveals weak green light and strong red light. Next, the energy transfer mechanism and spectral characteristics of near-infrared radiation were examined. Fluorosilicate glass has favorable conditions such as relatively low cost, high light transmittance, and good thermal stability. Ho3+ the emission cross-section and gain coefficient were calculated to be 0.51 x 10(-20) cm(2) and 0.903 cm(-1), respectively. Furthermore, given the Judd-Ofelt theory, calculated and analyzed the Ho3+/Yb3+ co-doped Omega(t) (t = 2, 4, 6) of 4.25, 2.45, and 0.8, respectively, indicating that the stimulated emission of Ho3+ was strong. The sample's maximum fluorescence lifetime at 2.0 mu m was 0.856 ms, which was 0.182 ms longer than that of silicate glass. This indicates that the addition of fluoride is beneficial to improve the fluorescence lifetime at 2 mu m. According to the testing results, Ho3+/Yb3+ co-doped fluorinated silicate glass has a promising development potential for broadband near-infrared fiber and laser materials.