TmP5O14晶体的上转换发光的研究

报道室温下TmP₅O₁₄晶体在脉冲DCM染料激光激发下产生的紫外和深紫色上转换发光现象.测量发现在300—500nm波长范围内主要有两组上转换荧光,一是较强的¹D₂→³H₆,³F₄的360和450nm的双光子荧光,另一是¹I6→³F₄的347nm的三光于荧光,发现了由 关键词：

STUDY ON UP-CONVERSION LUMINESCENCE RESEARCH OF TmP5O14 CRYSTAL

The up-conversion luminescence phenomenon of TmP₅O₁₄ crystal at room temperature pumped by pulsed DCM dye laser is studied. It is found that there appear strong 450 and 360 nm and weak 347 nm fluorescences. Through careful experiment al investigation and theoritical analysis, we find that the 450 and 360 nm radiations are ¹D₂→³F₄,³H₆ two-photon upconversion fluorescence and 347 nm radiation is ¹I₆→³F₄ three-photon fluorescence. The up-conversion process can be elucidated as follows: when a Tm³⁺ ion absorbs a first pumping photon and reaches the ³F₂ state from the ³H₆ bound state, the population of ³F₂ state falls down rapidly to the ³H₄, state due to the rather strong nonradiative relaxation. Then the excited state absorption from ³H₄ to ¹D₂ takes place and the 360 nm two-photon up-conversion fluorescence from ¹D₂ state is appears. Meanwhile, there is a small possibility for energy transfer between ¹D₂ state and ³H₄ state. It results in a converted population with respect to the ¹I₆ state and the 347 nm three-photon up-conversion fluorescence is appear, the up-con-version mechanism of which is a complicated process involving both the excited state absorption and the temperature of photons.