Desighn and Development of Infrared-to-Visible Upconversion Rare Earth Laser

我们获得了以下几个方面的研究结果：利用红外AlGaAs激光二极管800 nm的辐射，首次在掺Er^<3+>的重金属氧化物玻璃中观察到了有效的可见光上转换，发现上转换效率随基质玻璃中与稀土离子耦合的声子能量的变化而变化，Tm^<3+>掺杂玻璃在650 nm的DCM染料激光泵浦下，表现出紫外和蓝光上转换。Tm^<3+>上转换的主要机制是两种激发态的激发态吸收，明确了氧化物和几种氟化物玻璃中Er^<3+>和Nd^<3+>离子Judd-Ofelt强度参数的控制因素。在三个OMEGA_t参数中，OMEGA_6<151>与穆斯堡尔效应测量中的Eu同质异能位移有很强的相关性。这些现象可以用6s电子对5s轨道的屏蔽效应以及稀土和配位键的共价效应使5s轨道密度增加来解释。

We have obtained several research results listed below.It was possible for the first time to ovserve efficient visible upconverion in Er^<3+> doped heavy metal oxide glasses by 800nm radiation of infrared AlGaAs laser diode.The upconversion efficiency was found to vary with the phonon energy coupled with the rare earth ions in the host glass, which was observed in the phonon sideband spectra.The Tm^<3+> doped glasses exhibit uv and blue upconversion by 650nm pumping of DCM-dye laser. The main mechanism of Tm^<3+> upconversions was excited state absorption from two kinds of excited levels.Teh controlling factors of Judd-Ofelt intensity parameters were made clear for Er^<3+> and Nd^<3+> ions in oxide and several fluoride glasses. Among three OMEGA_t parameters, the OMEGA_6 showed a strong correlation between the ^<151>Eu isomer shift in Mossbauer effect measurement for the glass with the same composition. These phenomena could be well explained by the shielding effect on the 5dorbital by the 6s electron, the density of which is increased by the covalency effect of rare earth and ligand bond.