Investigation of intense mid-infrared emission in Ho3+/Yb3+/Er3+ triple-doped tellurite glass

Rare earth ion doping is considered to be a feasible way to improve the optical properties of glass in recent years. We investigate the luminescence characteristics of Ho3 + -Er3 + -Yb3 + triple-doped tellurite glass (TeO2-ZnO-WO3-La2O3) at 2.0 μm. A series of characterization analyses on the prepared samples, such as x-ray diffractometer (XRD) pattern, Raman spectrum, differential scanning calorimetry (DSC) curve analyses, absorption spectrum, emission spectrum, and fluorescence decay curve, were performed. XRD pattern and DSC curve analyses indicate that the glass sample exhibits a typical amorphous structure with excellent thermodynamic stability. Through the absorption spectrum, the position and intensity of the absorption peak of the glass sample can be detected. Under an excitation of 980 nm laser, the 2.0-μm emission peak intensity of the glass sample increases by about 1500%, which is attributed to the energy level transition among Ho3 + , Er3 + , and Yb3 + . By analyzing the energy level transition of Ho3 + , Yb3 + , and Er3 + ions, the energy transfer mechanism and fluorescence lifetime can be obtained, and then the fluorescence enhancement phenomenon of Ho3 + -Er3 + -Yb3 + triple-doped tellurite glass at 2.0 μm can be explained. It is demonstrated that the as-prepared Ho3 + -Er3 + -Yb3 + triple-doped tellurite glass has potential for the application of fiber lasers and fiber amplifiers.