Ultra-broadband 1.0 μm band emission spectroscopy in Pr3+/Nd3+/Yb3+ tri-doped tellurite glass.

Tellurite glasses doped with trivalent Pr3+, Nd3+ and Yb3+ ions were prepared using conventional high-temperature melt-quenching technique and their optical absorption, near-infrared emission, X-ray diffraction (XRD), Raman spectrum, and differential scanning calorimeter (DSC) curve were measured. Upon excitation at 488 nm, an ultra-broadband near-infrared emission extending from 800 to 1120 nm was found to appear owing to the overlapping of the emission bands centered at 900 and 1035 nm of Pr3+, 880 and 1060 nm of Nd3+ as well as 978 nm of Yb3+, respectively. The energy transfer mechanism among Pr3+, Nd3+ and Yb3+ ions which was responsible for the observed ultra-broadband near-infrared emission was investigated to understand the luminescent phenomena. In addition, Judd-Ofelt theory was applied to predict the radiative properties of doped rare-earth ions, and some important radiative parameters such as radiative transition probability, branching ratio and radiative lifetime were derived. Meanwhile, the structural information of amorphous nature and vibrational units was revealed by the XRD pattern and Raman spectrum. Also, the DSC curve displayed the good thermal stability to resist thermal damage for studied tellurite glass with high glass transition temperature. The results indicate that Pr3+/Nd3+/Yb3+ tri-doped tellurite glass is a promising material for ultra-broadband fiber lasers operating around 1.0 μm near-infrared band.