Er3+掺杂Ge-Ga-S-KBr硫卤玻璃的中红外发光和多声子弛豫的研究

用熔融急冷法制备了系列不同Er3+离子掺杂浓度的Ge-Ga-S-KBr硫卤玻璃，测试了样品折射率、吸收光谱、中红外荧光光谱。通过吸收光谱计算了Er3+离子吸收谱线的振子强度，应用Judd-Ofelt理论计算分析了Er3+离子在Ge-Ga-S-KBr硫卤玻璃中的强度参数Ωi ( i = 2 , 4 , 6) 、自发辐射跃迁几率A、荧光分支比?和辐射寿命?rad等光谱参数。研究了808nm激光泵浦下样品中红外荧光特性与掺杂浓度之间变化关系，并用Futchbauer-Ladenburg公式分别计算了2.8?m处的受激发射截面。结果表明，在808nm 激光泵浦下观察到了2.8?m中红外荧光，分别对应于Er3+： 4I11/2?4I13/2跃迁，当Er3+离子掺杂浓度从0.4wt%增加到1.0wt%时，中红外荧光强度都随相应增加，计算的Er3+:4I11/2?4I13/2跃迁多声子驰豫速率分别为37 s-1。

Mid-infrared emissions and multiphonon relaxation in Er3+-doped chalcohalide glasses

A serial of chalcogenide glasses based on Ge-Ga-S-KBr system doped with the different Er3+ ions were synthesized by melt-quenching technique. The refractive indexes, absorption spectra, mid-infrared emission spectra of samples were measured. The oscillator strength of absorption line of Er3+ ions has been calculated by using determination of absorption spectra. The intensity parameters (Ωi,i=2,4 ,6), transition probabilities (A), branching ratios (?) and radiative lifetimes (?rad) have been predicted for Er3+ ions in samples by using the Judd-Ofelt theory. The mid-infrared emission properties were investigated with the different Er3+ ion concentration under 808 nm laser excitation. The emission cross-section at 2.8?m was calculated using the theory of the Futchbauer- Ladenburg equation respectively. The results indicate that the fluorescence under 808 nm excitation with peak wavelength at 2.8mm was due to the Er3+: 4I11/2?4I13/2 transition respective. The intensity of the mid-infrared fluorescence were enhanced with the concentration increased of the Er3+ content from 0.4wt% to 1.0wt%. Multiphonon relaxation rates were 37 s-1 for the Er3+:4I11/2?4I13/2 transition separately.