Zhao Chun, Zhang Qinyuan, Yang Gangfeng, Jiang Zhonghong
Key Laboratory of Special Functional Materials of Ministry of Education and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641, China.
J Fluoresc. 2008 Jan;18(1):87-91. doi: 10.1007/s10895-007-0240-y. Epub 2007 Sep 6.
This paper reports on intense blue upconversion in Tm(3+)/Yb(3+) codoped TeO(2)-Ga(2)O(3)-R(2)O(R=Li, Na, K) glasses upon excitation with commercial available laser diode (LD). Effects of alkali ions on the Raman spectra, thermal stability and spectroscopic properties of the tellurite-gallium glasses have also been investigated. Energy transfer and the involved upconversion mechanisms have been discussed. Intense blue upconversion emission centered at 476 nm along with a weak red emission at 650 nm has been observed upon excitation of 977 nm LD, assigned to the transitions of 1G4-->3H6, and 1G4-->3H4 and/or 3F(2,3)-->3H6 of Tm(3+), respectively. The blue upconversion intensity has a cubelike dependence on incident pump laser power, indicating a three-photon process. However, a quadratic dependence of the 476 nm upconversion intensity on the incident pump laser power has been observed when samples under excitation of 808 nm LD due to a two-photon absorption process. Enhanced upconversion luminescence have been observed with replacing K(+) for Na(+) and Li(+).
本文报道了用商用激光二极管（LD）激发时，Tm(3+)/Yb(3+)共掺杂的TeO(2)-Ga(2)O(3)-R(2)O（R = Li、Na、K）玻璃中的强蓝光上转换。还研究了碱金属离子对碲酸盐-镓玻璃的拉曼光谱、热稳定性和光谱性质的影响。讨论了能量转移和相关的上转换机制。在用977 nm LD激发时，观察到了以476 nm为中心的强蓝光上转换发射以及650 nm处的弱红光发射，分别归因于Tm(3+)的1G4-->3H6、1G4-->3H4和/或3F(2,3)-->3H6跃迁。蓝光上转换强度与入射泵浦激光功率呈立方关系，表明是三光子过程。然而，当样品用808 nm LD激发时，由于双光子吸收过程，观察到476 nm上转换强度与入射泵浦激光功率呈二次关系。用K(+)替代Na(+)和Li(+)时，观察到上转换发光增强。
