Enhanced And Modulated Visible Luminescence Of Pr3+:Caf2 Crystal By Co-Doping R3+ (R=Y, Gd, Lu) Ions

A series of 0.6 at% Pr:CaF2-RF3 (R = Y3+, Gd3+, Lu3+) crystals have been successfully grown by the temperature gradient technique(TGT). The absorption spectra, fluorescence spectra, and fluorescence decay curves were measured and analyzed at room temperature. When the R3+ concentration is higher than a certain value, the diffraction peaks of Pr:CaF2-RF3 crystals were well indexed to the (Ca,Y)F-2 phase. By co-doping R3+ ion (R=Y3+, Gd3+, Lu3+), the spectral performance of the crystals could be significantly improved and the function effect is also different. For 0.6 at% Pr, 28.5 at% Y:CaF2 crystal, the fluorescence lifetime of P-3(0) energy level was fitted to be 45.46 mu s, and the emission cross sections of P-3(0)-> H-3(6) (605 nm), and P-3(0)-> F-3(2) (641 nm) were calculated to be 1.78 x 10(-20) cm(2), and 4.61 x 10(-20) cm(2) with the full width at half (FWHM) of 20.1 nm and 6.8 nm, respectively. The 0.6 at% Pr, 28.5 at% Y:CaF2 crystal could be favorble laser medium for ultra-fast laser opreration at 605 nm and 641 nm. For 0.6 at% Pr, 18 at% Gd:CaF2 and 0.6 at% Pr, 10 at% Lu:CaF2 crystals, the spectral quality factors cem.Tf of P-3(0)-> F-3(2) transition (642 nm) were calculated to be 614.18 x 10(-20) cm(2).mu s and 506.36 x 10(-20) cm(2).mu s with the FWHM of 3.7 nm and 5.3 nm. All the results show that 0.6 at% Pr, 18 at% Gd:CaF2 and 0.6 at% Pr, 10 at% Lu:CaF2 crystals are promising gain media for high-efficiency visible laser output at 642 nm, which would compete with commercial Pr: YLF crystal in the future. (C) 2021 Elsevier B.V. All rights reserved.