Yang Luyun, Dong Yongjun, Chen Danping, Wang Chen, Hu Xiao, Da Ning, Zhao Guangjun, Xu Jun, Jiang Xiongwei, Zhu Congshan, Qiu Jianrong
Opt Express. 2006 Jan 9;14(1):243-7. doi: 10.1364/opex.14.000243.
Infrared to ultraviolet and visible upconversion luminescence was demonstrated in trivalent cerium doped YAlO(3) crystal (Ce(3+): YAP) under focused infrared femtosecond laser irradiation. The fluorescence spectra show that the upconverted luminescence comes from the 5d-4f transitions of trivalent cerium ions. The dependence of luminescence intensity of trivalent cerium on infrared pumping power reveals that the conversion of infrared radiation is dominated by three-photon excitation process. It is suggested that the simultaneous absorption of three infrared photons pumps the Ce(3+) ion into upper 5d level, which quickly nonradiatively relax to lowest 5d level. Thereafter, the ions radiatively return to the ground states, leading to the characteristic emission of Ce(3+).
在聚焦红外飞秒激光辐照下，在三价铈掺杂的YAlO(3)晶体（Ce(3+):YAP）中实现了从红外到紫外和可见光的上转换发光。荧光光谱表明，上转换发光来自三价铈离子的5d-4f跃迁。三价铈发光强度对红外泵浦功率的依赖性表明，红外辐射的转换主要由三光子激发过程主导。研究表明，同时吸收三个红外光子将Ce(3+)离子泵浦到较高的5d能级，该能级迅速无辐射弛豫到最低的5d能级。此后，离子辐射跃迁回到基态，导致Ce(3+)的特征发射。
