Ho3+掺杂GeO2-Ga2O3-Li2O-BaO-La2O3玻璃的光谱和增益特性的计算

用高温熔融法制备了不同Ho3+浓度掺杂的65GeO2-12Ga2O3-8Li2O-10BaO-5La2O3-χHo2O3锗酸盐玻璃.从吸收光谱出发,应用Judd-Ofelt理论,获得了Ho3+离子的跃迁强度参量（Ω2,Ω4,Ω6）,并由此计算了Ho3+离子的自发辐射跃迁几率A,荧光分支比β,辐射能级寿命τ等光谱参量.根据McCumber理论,计算了Ho3+离子能级5I8→5I7（2.0 μm）跃迁的吸收截面和受激发射截面,同时也获得了相应的反映粒子数反转的增益截面光谱.钬掺杂的锗酸盐玻璃,其增益截面的最大值比所报道的氟锆铝酸盐玻璃大.结果表明,Ho3+掺杂的锗酸盐玻璃在2.0 μm附近波段的中红外激光器中将有一定的应用前景.

Optical Spectra and Calculation for the Gain Properties of Ho~(3+)-Doped GeO_2-Ga_2O_3-Li_2O-BaO-La_2O_3 Glasses

Glasses with the compositions of 65GeO2-12Ga2O3-8Li2O-10BaO-5La2O3 doped with different Ho3+ concentration 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 Ho3+ were calculated,by which the radiative transition probabilities,fluorescence branching ratios and radiative lifetimes were obtained.According to McCumber theory,the absorption and emission cross-sections corresponding to the 5I8→5I7 transitions of Ho3+ (at 2.0μm) were obtained,and respective gain cross section spectra were also computed as a function of population inversion.For Ho3+-doped germanate glasses,the maximum gain cross-section reached a value higher than that reported for fluorozircoaluminate glasses.Hence,these Ho3+-doped germanate glasses have an advantage for application in lasers at about 2.0μm mid-infrared wavelength.