Optical properties of Er3+/Yb3+ co-doped bismuth calcium borate glass system for NIR lasers and fiber amplifiers

An Er3+/Yb3+ co-doped bismuthate (Bi2O3-B2O3-CaO) glass was prepared by melt quenching method. The samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), absorption and emission spectroscopy. The Judd-Ofelt parameters (Ωλ) were determined from the intensity of the absorption band to calculate the radiation parameters, such as the radiation lifetime (τrad), radiation transition probability (Arad) and branching ratio (βJJ′) of 4I13/2 laser conversion of Er3+ ions. The effective emission bandwidth (ΔλP), stimulated emission cross section (σse) and gain bandwidth (σse × Δλp) were determined on the emission spectra, and the optimum doping concentration of Er2O3 was 0.5 mol%. The present work indicates that Er3+/Yb3+ co-doped bismuth calcium borate glass can be promising materials for solid state NIR lasers and fiber amplifiers.