研究了Tm3+掺杂氟锆酸盐玻璃的2 μm发光特性。通过吸收光谱,运用Judd-Ofelt(J-O)理论计算了J-O强度参量Ωt(t=2,4,6)以及Tm3+离子在玻璃中的自发辐射跃迁几率、荧光分支比和辐射跃迁寿命等光谱参数。采用808 nm激光二极管(LD)抽运,获得了Tm3+离子在氟锆酸盐玻璃中的近2 μm发射光谱。Tm3+离子在玻璃中的3F4→3H6跃迁峰值波长位于1.82 μm处。研究表明,随着Tm3+离子浓度的增加,Tm3+离子之间发生明显的交叉弛豫过程(3H4→3F4,3F4→3H6),从而使得1.82 μm处荧光强度明显增强,但当掺杂浓度进一步增加达到一定程度后,基于三能级稀土离子的浓度猝灭效应,该荧光强度明显降低。研究计算了氟锆酸盐玻璃中Tm3+:3F4→3H6跃迁对应的受激发射截面,结果表明,受激发射截面受Tm3+掺杂浓度的影响不大。

2 μm emission properties of Tm3+ in fluorozirconate glass were reported. The Judd-Ofelt (J-O) intensity parameters Ωt (t=2,4,6),spontaneous emission probability,fluorescence branching ratio,and the radiative lifetime were calculated on the basis of Judd-Ofelt theory by measuring the absorption spectra of the glass. The effects of Tm3+ ion concentration on the optical parameters were discussed. From the measured emission spectra of glass,it was found that the peak wavelength of Tm3+:3F4→3H6 transition is located at 1.82 μm in the Tm3+-doped fluorozirconate glass. It was also found that the cross relaxation (3H4→3F4,3F4→3H6) between the Tm3+ ions occurred with the Tm3+ ion concentration increasing,which leads to the increasing magnitude of 3F4→3H6 transition. Due to the concentration quenching mechanism of three-energy level ions,the intensity of luminescence decreased obviously. The stimulated emission cross section of Tm3+:3F4→3H6 transition was calculated by using Mcumber theory. The results show that doping concentration has little effect on the emission cross section of Tm3+ in the present fluorozirconate glass.