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Neodymium doped phosphate glasses have been prepared by the semi-continuous melting technique. Their absorption and emission spectra have been recorded at room temperature. The Judd-Ofelt theory has been applied to evaluate the stimulated emission cross sections of 4F3/2→4I11/2 transition for Nd3+. The higher stimulated emission cross section, 4.0×10-20cm2, is obtained. The fluorescence decays of the 4F3/2→4I11/2 transition of Nd3+ are measured for the samples doped (0.7-10) wt% of Nd2O3 at room temperature. The concentration quenching of Nd-doped phosphate glass is mainly attributed to cross-relaxation and energy migration. The site-dependent properties of fluorescence spectra and the fluorescence lifetime of the Nd3+-doped phosphate glass (with 2.2wt%Nd2O3) are studied using laser-induced fluorescence line narrowing techniques, and the site-to-site variations of optical properties are observed at low temperature. 相似文献
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新型蓝光衬底材料LiAlO_2晶体的生长和缺陷分析 总被引:3,自引:0,他引:3
LiAlO2和GaN的晶格失配率只有1.4%,是一种很有希望的GaN外延生长衬底材料。本文利用温度梯度法生长出了透明的LiAlO2单晶,并通过化学浸蚀、光学显微镜、透射电子显微镜、同步辐射X射线貌相术对晶体中的缺陷进行了检测。结果表明:LiAlO2在钼坩埚中无籽晶自由凝固结晶时,是沿(100)方向生长。用温度梯度法生长的LiAlO2晶体质量良好,晶体中无气泡和包裹物。在LiAlO2(100)晶面上测得的位错密度为(3.8~6.0)×104cm-2,晶体中的主要缺陷为亚晶界或镶嵌结构,可能是由于温场不稳定、生长速率太快造成的。 相似文献
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高浓度掺钕钇铝石榴石(Nd∶YAG)晶体的光谱与激光特性 总被引:1,自引:0,他引:1
测量了高掺杂浓度Nd∶YAG晶体的吸收光谱和荧光寿命。晶体的主吸收峰在 80 8nm处 ,Nd掺杂的摩尔分数为 0 0 30的Nd∶YAG晶体的吸收系数高达 2 0 7cm-1,荧光寿命为 15 0 μs,存在浓度猝灭。进行了钛宝石激光抽运高掺杂浓度Nd∶YAG和Nd∶YVO4 晶体的激光性能对比实验 ,所用Nd∶YAG晶体摩尔分数为 0 0 2 0和 0 0 2 5 ,激光斜率效率分别为 2 9 7%和 32 % ;Nd∶YVO4 晶体摩尔分数为 0 0 30 ,激光斜率效率为 34 7% ,表明了高浓度Nd∶YAG晶体在激光性能上与高浓度的Nd∶YVO4 晶体相当 相似文献
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用AgK_α辐射X射线透射形貌术成功地显示了Nd:YAG晶体中的缺陷性质及其分布.在用引上法及温梯法生长的晶体中存在数种缺陷如生长条纹、沉淀粒子、刃位错、螺应错以及由于位错运动而形成的混合型位错.实验结果与光学方法所得结果相一致,但在判明位错的性质方面,X射线形貌术有其独特的优点. 相似文献