Er3+掺杂氧氟锗硅酸盐玻璃的频率上转换研究

研究了基质玻璃成分对Er^3 掺杂氧氟锗硅酸盐玻璃上转换光谱和Raman光谱的影响，分析了氧氟锗硅酸盐玻璃中Er^3 的上转换发光机理。结果表明：通过975nm的激光二极管激发，在室温下同时观察到强烈的绿光(529，545nm)和红光(657nm)发射，分别是由于Er^3 的。H11/2→^4I15/2,^4S3/2→^4I15/2,和^4F9/2→^4I15/2跃迁，且均为双光子吸收过程。与545nm的绿光发射相比，657nm的红光发光强度比较微弱。随GeO2浓度的增加，基质玻璃的最大声子能量下降，导致无辐射跃迁几率降低，因此绿光和红光的发光强度都增强，但是其对绿光的影响大于红光。

INVESTIGATION ON FREQUENCY UPCONVERSION OF Er3+-DOPED OXYFLUORIDE GERMANOSILICATE GLASSES

Effect of host composition on upconversion and Raman spectra of Er~(3+)-doped oxyfluoride germanosilicate glasses was investigated, and upconversion mechanisms of Er~(3+) in oxyfluoride germanosilicate glasses were analyzed. The results show that intense green and red emission centered around 529, 545 nm, and 657 nm are simultaneously observed at room temperature under 975 nm diode laser excitation. These emissions are corresponding to the Er~(3+ )energy level transitions of ~(2)H_(11/2 )to ~(4)I_(15/2), ~(4)S_(3/2 )to~( 4)I_(15/2), and ~(4)F_(9/2 )to~(4)I_(15/2) respectively. A two-photon upconversion process is assigned to the green and red emission, and the intensity of red emission at 657 nm is relative weaker than that of the green emission at 545 nm in Er~(3+)-doped oxyfluoride germanosilicate glasses. With increasing GeO_(2) concentration, the highest phonon energy of the glass hosts is lowered, which results in lowering the probability for nonradiative transition rate, and consequently upconversion luminescence intensities of green and red emission are enhanced. But the results show that the concentration of GeO_(2) has much influence on the green emission than the red emission.