掺Nd3+玻璃微球发射光谱研究

采用粉末喷烧法制备了掺Nd^3 高折射率TiBa玻璃微球，主要成分为TiO2，BaO和SiO2，微球直径在30μm左右。在带有显微镜的光谱仪上，用514nm激光照射微球的边缘，测量了它们的发射光谱，观察到了微球腔效应导致的光谱结构共振。在较低泵浦阈值(2mW)下，获得了Nd^3 的激射发光。利用光学微腔理论讨论了玻璃微球荧光光谱中的形貌共振，实验结果与计算结果相符。

Photoluminescence Spectra of Trivalent Neodymium Doped TiBa Glass Microspheres

In this work, TiBa glass microspheres doped with Nd3+ for morphology-dependent resonances of emission were designed and prepared. The emission spectra of TiBa glass plate and TiBa glass microspheres (45 and 13 microm in diameter) under 514 nm excitation were measured. The authors observed many regularly spaced, sharp peaks in the emission spectra of a Nd3+-doped glass microsphere. Based on the Mie scattering theory, the wavelength separation between the adjacent resonant peaks for the 45 microm sphere was calculated to be 3.0 for 810 nm. This value agrees well with the observed peak separation (3.1 nm), which indicates the contribution of the whispering gallery modes. The emission intensities of a Nd3+-doped TiBa glass microsphere (13 microm in diameter) in the 901.69 nm region were plotted against the excitation laser power. The emission intensities of the microsphere exhibit the linear dependence at the low excitation power (<2 mW). The 901.69 nm emission intensity of the microsphere steeply increases at the excitation power of 2 mW, which can be ascribed to the laser operation.