Tm^(3+)掺杂锗镓酸盐玻璃的2μm中红外光谱特性  

2μm Mid-Infrared Optical Spectra of Tm^(3+)-Doped Germanium Gallate Glasses

作　　者：夏海平[1] 林琼斐[1] 章践立[1] 张勤远[2] 

机构地区：[1]宁波大学光电子功能材料重点实验室,浙江宁波315211 [2]华南理工大学光通信材料研究所特种功能材料教育部重点实验室,广东广州510640

出　　处：《中国稀土学报》2009年第5期603-608,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金(60777030);宁波市科技局(2007B10053);宁波市重点实验室开放基金(2007A22010);宁波大学王宽诚幸福基金资助

摘　　要：用高温熔融法制备了Tm2O3掺杂浓度分别为1.526%,3.006%,5.836%,11.028%,15.678%(质量分数,以下同)的65GeO2-12Ga2O3-10BaO-8L i2O-5La2O3(摩尔比)玻璃。从其吸收光谱特性出发,应用Judd-O felt理论,计算了Tm3+离子的J-O强度参数(Ω2,Ω4,Ω6)及Tm3+离子各激发态能级的自发跃迁几率、荧光分支比以及辐射寿命等光谱参量。在808 nm波长光的激发下,研究了不同Tm3+掺杂浓度玻璃在~1.47μm与~1.8μm的荧光特性,发现当Tm2O3掺杂浓度约达到~3.006%时,在1.8μm处的荧光强度达最大;然后随着掺杂浓度的增大,其荧光强度反而降低。本文从Tm3+离子间的能量交叉弛豫效应与浓度猝灭效应解释了这一荧光强度变化的现象。同时,根据M c-Cumber理论,计算了Tm3+离子能级3F4→3H6(1.8μm)跃迁的吸收截面和受激发射截面,该荧光的受激发射截面峰值比氟锆铝酸盐玻璃大。由于该玻璃材料表现出较好的光谱性能,因此该材料可望成为~2.0μm波段中红外光纤激光器的候选基质材料。Glasses with the compositions of 65GeO2- 12Ga2O3-10BaO-8Li2O-5La2O3 （molar ratio） doped with 1.526%, 3.006%, 5.836%, 11.028%, and 15.678% （mass fraction） Tm2O3, respectively, were fabricated by conventional melting method. According to the absorption spectra and the Judd-Ofeh theory, the J-O strength parameters （Ω2, Ω4, Ω6 ） were calculated, by which the radiative transition probabilities, branching ratios and radiative lifetimes were obtained. The infrared emission spectra （with 808 nm LD excitation） at - 1.47 and - 1.8 μm of various concentrations Tm^3＋ -doped glasses were studied. The emission intensity at - 1. 8 μm reached the maximum when the Tm2O3-doping concentration was near - 3. 006 wt% （ 1.0 mol% ）, and then decreased as doping concen- tration increased further. The mechanism of the change of fluorescence intensity was explained from the cross -relaxation effect and the concentration quenching effect of Tm^3 ＋. Meanwhile, according to McCumber theory, the absorption and emission crosssections corresponding to the ^3F4→^3H6 transitions of Tm^3 ＋ at 1.8 μm were obtained. For Tm^3 ＋ -doped germanate glasses, the maximum emission cross-section reached a value higher than that reported for fluorozircoaluminate glasses. It was expected to be a favorable candidate host for - 2.0 μm mid-infrared laser because the glass showed favorable optical spectra.

关 键 词：掺铥锗镓酸盐玻璃 光谱性质 交叉弛豫 发射截面 稀土 

分 类 号：TQ171[化学工程—玻璃工业]