用高温熔融法制备了不同Tm3+摩尔分数掺杂的摩尔分数比为0.3(SiO2)0.1(Al2O3)0.1(AlF3)0.5(PbF2)x(Tm2O3)(摩尔分数x=0.5%,1.0%,2.0%,3.0%)玻璃。从吸收光谱特性出发,应用Judd-Ofelt理论,计算得到了Tm3+的J-O强度参量(Ω2,Ω4,Ω6)及Tm3+各激发能级的自发辐射跃迁概率、荧光分支比以及辐射寿命等光谱参量。在808 nm波长的激光二极管激发下,研究了不同Tm3+掺杂摩尔分数下玻璃在约1.47 μm与约1.8 μm处的荧光特性,在掺杂摩尔分数约达到2.0%时,在1.8 μm处的荧光强度达最大,然后随着掺杂摩尔分数的增大,其荧光强度反而降低。作者从Tm3+的交叉弛豫与摩尔分数猝灭效应解释了这一荧光强度变化的规律,同时,根据McCumber理论计算了Tm3+跃迁3H6→3F4的吸收截面和跃迁3F4→3H6的受激发射截面。

Glasses with the compositions of 0.3SiO2-0.1Al2O3-0.1AlF3-0.5PbF2 doped with different Tm3+ concentration (x=0.5 mol%,1.0 mol%,2.0 mol%,3.0 mol%) were fabricated by conventional melting method. According to the absorption spectra and the Judd-Ofelt theory, the J-O strength parameters (Ω2,Ω4,Ω6) of Tm3+ were calculated, by which the radiative transition probabilities, fluorescence branching ratios and radiative lifetimes were obtained. The infrared emission spectra (with 808 nm laser diode excitation) at ～1.47 μm and ～1.8μm of various concentration Tm3+-doped glasses were studied. The emission intensity at 1.8 μm reaches to the maximum when the Tm3+-doping concentration is near to be 2.0 mol% and then decreases at higher concentration. The mechanism of the change of the fluorescence intensity was explained from the cross-relaxation effect and the concentration quenching effect of Tm3+. The absorption cross section of 3H6→3F4 transition and the stimulated emission cross section of 3F4→3H6 transition of Tm3+ have also been calculated according to McCumber theory.