Improvement of ultra-broadband near-infrared emission at around 1.0 μm in Nd3+-Er3+-Pr3+ tri-doped tellurite glasses

Nd3+-Er3+-Pr3+ tri-doped tellurite glasses with lower phonon energy (768 cm(-1)) were prepared by conventional melt-quenching method. Under the excitation of 488nm, an ultra-broadband emission from 760 to 1150 nm with full-width at half-maximum (FWHM) of about 262 nm was observed in the prepared Nd3+-Er3+-Pr3+ tri-doped glass sample, larger than that of the recently reported glasses. The DSC curve shows that the prepared tellurite glass has high glass transition temperature (T-g=382 degrees C) and good thermal stability (Delta T=203 degrees C). The gain coefficient, maximum absorption and emission cross section of Nd3+-Er3+-Pr3+ tri-doped tellurite glass for Nd3+:F-4(3/2) -> I-4(9/2) and Er3+:I-4(11/2) -> I-4(15/2) transitions are calculated as 0.41 cm(-1), 0.80 x 10(-20) cm(2), 1.07 x 10(-20) cm(2), 0.35 cm(-1), 0.37 x 10(-20) cm(2) and 0.45 x 10(-20) cm(2), respectively. Compared with the recently reported glasses, these values were effectively improved. This means that the prepared tellurite glass has better fluorescence emission and laser gain performance.