Energy transfer and luminescence properties of Tm3+ ions in calcium fluoroborate glasses for fiber amplifiers

► Spectroscopic properties of Tm3+ ions in Calcium fluoroborate glasses were studied. ► Optical absorption and photoluminescence spectra were interpreted. ► Theoretical as well as experimental results were correlated. ► Quenching of emission intensities were explained using cross-relaxation mechanisms. ► Emission cross-sections were theoretically predicted.