Broadband and flat near-infrared emission from Er3+/Tm3+ codoped to tellurite glass for amplifier applications

摘要

Er3+/Tm3+ codoped tellurite glasses have been synthesized using the melt-quenching technique; they are characterized by measurements of absorption spectrum, luminescence spectrum, fluorescence decay, Raman spectrum, and differential scanning calorimeter curve. Under the excitation of an 808 nm laser diode (LD), an extremely flat and broadband near-infrared emission with the full width at half-maximum of similar to 160 nm has been obtained in tellurite glass doped with optimized Er3+ - Tm3+ concentrations. This broadband and flat fluorescence emission is located in the region of 1350-1650 nm and covered the E, S, C, and L bands, which originate from the spectral overlapping of 1.53 mu m band emission of Er3+ : I-4(13/2) -> I-4(15/2) transition and 1.47 mu m band emission of Tm3+ : H-3(4) -> F-3(4) transition. The Judd-Ofelt theory was applied to the absorption spectrum, and the radiative properties such as transition probability, branching ratio, and radiative lifetime of Er3+ and Tm3+ ions have been determined to evaluate the potential luminescence characteristics. The time-resolved fluorescence decay of Er3+ and Tm3+ ions demonstrated the existence of energy transfers between them, and the energy transfer micromechanism was further investigated quantitatively. The results indicate that tellurite glass codoped with appropriate amounts of Er3+ - Tm3+ ions is promising for applications in broadband optical fibers and photonic devices. (C) 2020 Optical Society of America