Er^(3+)掺杂钨酸铅晶体的发光和光谱特征

Luminescence and Spectra Characteristics of Er^(3+)-doped PbWO_4 Single Crystals

本试验测试了Er3+掺杂钨酸铅晶体(PbWO4:Er3+)的吸收光谱,依据J-O理论,首次计算报道了光谱项特征:J-O强度参数、量子荧光效率、荧光分支比等,Ω2=3.75×10-20cm2,Ω4=0.67×10-20cm2,Ω6=0.41×10-20cm2。计算证实,PWO:Er3+中几乎有80%的激发能量非辐射跃迁转移致4I13/2能级,4I13/2的计算寿命是5200μs,J-O计算显示,在PWO中产生4I13/2→4I15/2和发射1.53μm.有高的几率。讨论了不同浓度Er3+掺杂对于吸收系数和PbWO4晶体光学吸收边的影响,讨论了Er3+掺杂PbWO4晶体的光致发光和X射线激发发光光谱,PbWO4:Er3+晶体中存在着从PbWO4基质到Er3+离子的能量传递,发光光谱的分析表明,这种能量传递是共振能量传递。

The dependence of absorption coefficient and the optical absorption edges on the doping levels of Er^3＋ ion were investigated. Based on the J-O theory, the phenomenological intensity parameters, intermanifold luminescence branching ratios and irradiative lifetime of the PWO： Er^3＋ crystals were calculated with Ω2=3.75×10^-20cm^2,Ω4=0.67×10^-20cm^2,Ω6=0.41×10^-20cm^2. It shows that the high rates of nonradiative relaxation from the excited states to the level ^4I13/2 ensure its effective population,and consequently there is a possibility of generation of stimulated emission based on the ^4I13/2→^4I15/2 transition. The efficient luminescence in the visible wavelength region from Er^3＋ doped in PbWO, is reported. Luminescence experiments demonstrate that excitation into the PbWO4 host is followed by an efficient energy transfer towards Er^3＋ ions with the anresonant energy transfer to Er^3＋ ions.