This paper reports on microcrystals with deep tissue penetration depth, strong red light emission, and thermometric function. The red light emission of NaLuF 4 :20 % Er 3+ /1 % Tm 3+ /10 % Yb 3+ microcrystals is exceptionally strong, thanks to the introduction of Tm 3+ and Yb 3+ ions energy capture centers. In bioimaging, the 1532 nm laser exhibits deeper imaging depth due to weak photon scattering and autofluorescence. Furthermore, red light emission has the greatest tissue penetration depth in the visible region. The luminescence intensity and tissue penetration depth of both the excitation and emission light make them suitable for deep tissue imaging. We investigated temperature sensing performance of NaLuF 4 :20 % Er 3+ /1 % Tm 3+ /10 % Yb 3+ microcrystals, and found that the maximum relative sensitivity of LIR (I 521 /I 540 ) reaches 0.92 %K −1 . The microcrystals NaLuF 4 :20 % Er 3+ /1 % Tm 3+ /10 % Yb 3+ are anticipated to have application in deep tissue imaging and temperature sensing.
Limin Wu,Yihua Pan,Shoulei Xu,Peng Zhang,Wenxia Wu,Yan Hao,Shengdi Ta,Yazhao Wang,Bernard Albert Goodman,Wen Deng
High-quality cubic YSZ crystals were designed with various contents of Er 3+ , Tm 3+ and Yb 3+ to produce white light emission, and grown by the optical floating zone method. The up-conversion luminescence spectra of the crystals under 980 nm laser irradiation show three distinct groups of emission peaks at ∼473 nm (blue) generated by the Tm 3+ 1 G 4 → 3 H 6 transition, 531 and 547 nm (green) from the Er 3+ 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions, and 640 and 662 nm (red) from the Er 3+ 4 F 9/2 → 4 I 15/2 transition. The optical power curve obtained by plotting the up-conversion luminescence intensity against the laser power shows that the blue emission involves a three-photon process, whilst both the green and red emissions are the results of two-photon processes. Overall white light emission was observed with the crystal prepared with 0.05 mol% Er 2 O 3 , 0.5 mol% Tm 2 O 3 and 2.0 mol% Yb 2 O 3 , and this crystal is suitable for use in highly efficient white light emission devices.
危险品化学品经营许可证（带存储）