摘要
测试了掺Er碲酸盐玻璃在 974nmLD泵浦下的吸收光谱、荧光光谱和上转换光谱 ,应用McCumber理论计算了Er3 + 的受激发射截面 ,分析了碲酸盐玻璃中Er3 + 离子的上转换发光机制 ,研究了Yb3 + 离子对Er3
The absorption spectra of Er 3+ ion and Yb 3+ ion in tellurite glass were investigated. The peak absorption were marked according to the absorption transition of Er 3+ and Yb 3+ , the energy levels of Er 3+ and Yb 3+ ions in tellurite glass were obtained according to the absorption spectra. The emission spectrum of Er 3+ ion in tellurite glass was studied. The stimulated emission cross section was calculated using McCumber theory and the FWHM was obtained according to the emission spectrum. Er 3+ ion show higher emission cross section( σ p=7 5×10 -21 cm 2) and larger FWHM (FWHM=66nm) in tellurite glass than those in other glass hosts, which are very important parameters for optical amplifiers to realize broadband and high gain amplification. The upconversion spectra of Er 3+ ion in tellurite glasses were measured and analyzed. The much lower phonon energy of tellurite glass makes it has different upconversion mechanism compared with other glasses with relative higher phonon energy. The relative longer lifetime of 4I 11/2 level of Er 3+ ion in tellurite glass produces the upconversion process 4I 11/2 + 4I 11/2 → 4F 7/2 + 4I 15/2 much more serious, and the four emission transitions 4F 7/2 → 4I 15/2 , 2H 11/2 → 4I 15/2 , 4S 3/2 → 4I 15/2 and 4F 9/2 → 4I 15/2 which corresponds to 486,530,550 and 660nm emission, respectively, become obvious. Furthermore, the upconversion intensity enhances with the increase of Yb 3+ concentration. Upconversion emission is very harmful for fiber amplifiers, which not only reduces the efficiency of bump light, but also deteriorates the noise figure of the amplifiers , so it is important to reduce upconversion phenomenon as much as possible. The energy transfer mechanism between Er 3+ and Yb 3+ ion were analyzed. The energy transfer coefficients and efficiencies between Yb 3+ and Er 3+ were calculated. At a certain Yb 3+ concentration, the forward energy transfer coefficient and efficiency hardly change while the back energy transfer coefficient and efficiency increase monotonically. So the effective sensitization of Yb 3+ to Er 3+ is appropriate only at a certain range of Yb 3+ concentration. The right selection of Yb 3+ concentration is needed in order to realize effective bump.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2002年第5期485-490,共6页
Chinese Journal of Luminescence
基金
国家自然科学基金资助项目 (699880 0 6)
上海市光科技资助项目
