The limitation of the random walk theory of energy transfer between rare earth ions in crystals published in literatures is pointed out in this paper. A modified model, which can be used in any level of rare earth ion...The limitation of the random walk theory of energy transfer between rare earth ions in crystals published in literatures is pointed out in this paper. A modified model, which can be used in any level of rare earth ion concentration when the interaction between donor and acceptor is different from that between donors, is introduced. This model has been applied to analyze the measured fluorescence lifetimes of Yb3+:YAl3(BO3)4 with a series of Yb3+ concentrations.展开更多
We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a...We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a hydrothermal process. The fluorescence spectra and decay curves were measured at room temperature. The fluorescence intensity of F--tridoped samples is about 3 times that for the non F--doped sample. The fluorescence quantum efficiency can be enhanced by 21% when the atomic ratio of F to W was 0.7.展开更多
Pr^(3+)-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^(3+) i...Pr^(3+)-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^(3+) ions were investigated. The crystalline phase and microstructure of the LiYF_4 nanocrystals were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM), respectively. Compared with those of Pr^(3+)-doped glass(Pr^(3+):PG), the sharp absorption and emission bands of Pr^(3+)-doped glass-ceramic(Pr^(3+):GC) reveal parts of Pr^(3+) ions are incorporated into LiYF_4 nanocrystals. The peak absorption cross-section at 443 nm(~3H_4 → ~3P_2) adds to 110% and the full width at half maximum(FWHM) for the band around 443 nm reduces from 22 to 14 nm after crystallization. The fluorescence lifetime of the ~3P_0 multiplet of Pr^(3+) ions increases from 5.35 to 11.14 μs after crystallization. The results indicate that this glass-ceramic is promising to be a visible laser material.展开更多
A Sr3Yb2(BO3)4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 (BO3)4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group P...A Sr3Yb2(BO3)4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 (BO3)4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750(8), b=15.9265(14), c=8.6776(9), V=1019.25(18)3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ(MoKa)=0.71073, μ= 33.835 mm-1 , F(000)=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I>2σ(I). The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2+ and Yb3+ occupy statistically three independent sites with a Cm and two C1 local symmetries.展开更多
Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communi- cation, medicine, laser-range-finding, lidar, etc. Er3+ and Yb3+ co-doped crystal pumped by diode laser around 976 nm is an attractive...Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communi- cation, medicine, laser-range-finding, lidar, etc. Er3+ and Yb3+ co-doped crystal pumped by diode laser around 976 nm is an attractive method for obtaining 1.5～1.6 μm laser in compact device with high output beam quality. In this paper, the recent research and progress of several important Er3+ and Yb3+ co-doped laser crystals at 1.5～1.6 μm in authors’ lab are reported.展开更多
End-pumped by a 976 nm diode laser,a high-repetition-rate Er:Yb:YAl3(BO3)4 microchip laser passively Q-switched by a Co2+:MgAl2 O4 crystal is reported.At a quasi-continuous-wave pump power of 20 W,a 1553 nm passively ...End-pumped by a 976 nm diode laser,a high-repetition-rate Er:Yb:YAl3(BO3)4 microchip laser passively Q-switched by a Co2+:MgAl2 O4 crystal is reported.At a quasi-continuous-wave pump power of 20 W,a 1553 nm passively Q-switched laser with the repetition rate of 544 kHz,pulse duration of 8.3 ns,and pulse energy of 3.9 μJ was obtained.To the best of our knowledge,the 544 kHz is the highest reported value for the 1.5 μm passively Q-switched pulse laser.In the continuous-wave pumping experiment,the maximum repetition rate of 144 kHz with the pulse duration of 8.0 ns and pulse energy of 1.7 μJ was obtained at the incident pump power of 6.3 W.展开更多
Diode-pumped acousto-optic Q-switched pulse laser at 1.5-1.6 μm is obtained in an Er3+:Yb3+:LuAl3 (BO3)4 crystal. Single-pulse laser operation with slope efficiency of 14% and threshold of approximately 100 mW is rea...Diode-pumped acousto-optic Q-switched pulse laser at 1.5-1.6 μm is obtained in an Er3+:Yb3+:LuAl3 (BO3)4 crystal. Single-pulse laser operation with slope efficiency of 14% and threshold of approximately 100 mW is realized at an average absorbed pump power of 314 mW and repetition frequency of 20 kHz. Output pulse energy is 67 μJ. The effects of pulse repetition frequency, absorbed pump power, and duty cycle on the wavelength and pulse profile of the Q-switched Er3+:Yb3+:LuAl3(BO3)4 laser are also investigated.展开更多
基金the National Natural Science Foundation of China (Nos. 50590405)the Natural Science Foundation of Fujian Province (No. A0610031)
文摘The limitation of the random walk theory of energy transfer between rare earth ions in crystals published in literatures is pointed out in this paper. A modified model, which can be used in any level of rare earth ion concentration when the interaction between donor and acceptor is different from that between donors, is introduced. This model has been applied to analyze the measured fluorescence lifetimes of Yb3+:YAl3(BO3)4 with a series of Yb3+ concentrations.
基金Supported by the National Natural Science Foundation of China(No.51002152)the Natural Science Foundation of Fujian Province(No.2010J05125)
文摘We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a hydrothermal process. The fluorescence spectra and decay curves were measured at room temperature. The fluorescence intensity of F--tridoped samples is about 3 times that for the non F--doped sample. The fluorescence quantum efficiency can be enhanced by 21% when the atomic ratio of F to W was 0.7.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)
文摘Pr^(3+)-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^(3+) ions were investigated. The crystalline phase and microstructure of the LiYF_4 nanocrystals were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM), respectively. Compared with those of Pr^(3+)-doped glass(Pr^(3+):PG), the sharp absorption and emission bands of Pr^(3+)-doped glass-ceramic(Pr^(3+):GC) reveal parts of Pr^(3+) ions are incorporated into LiYF_4 nanocrystals. The peak absorption cross-section at 443 nm(~3H_4 → ~3P_2) adds to 110% and the full width at half maximum(FWHM) for the band around 443 nm reduces from 22 to 14 nm after crystallization. The fluorescence lifetime of the ~3P_0 multiplet of Pr^(3+) ions increases from 5.35 to 11.14 μs after crystallization. The results indicate that this glass-ceramic is promising to be a visible laser material.
基金Supported by the National Natural Science Foundation of China (51002152)the Natural Science Foundation of Fujian Province (2010J05125)
文摘A Sr3Yb2(BO3)4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 (BO3)4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750(8), b=15.9265(14), c=8.6776(9), V=1019.25(18)3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ(MoKa)=0.71073, μ= 33.835 mm-1 , F(000)=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I>2σ(I). The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2+ and Yb3+ occupy statistically three independent sites with a Cm and two C1 local symmetries.
基金Supported by the National Natural Science Foundation of China (No. 50590405 and 50802094)the Major Programs of the Chinese Academy of Sciences (No. SZD08001-1)+1 种基金the Natural Science Foundation of Fujian Province (No. 2008J0173)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communi- cation, medicine, laser-range-finding, lidar, etc. Er3+ and Yb3+ co-doped crystal pumped by diode laser around 976 nm is an attractive method for obtaining 1.5～1.6 μm laser in compact device with high output beam quality. In this paper, the recent research and progress of several important Er3+ and Yb3+ co-doped laser crystals at 1.5～1.6 μm in authors’ lab are reported.
基金supported by the National Natural Science Foundation of China (Nos.61875199 and 61975208)Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB20000000)Science and Technology Service Network Initiative of the Chinese Academy of Sciences (No.KFJ-STS-QYZX-069)。
文摘End-pumped by a 976 nm diode laser,a high-repetition-rate Er:Yb:YAl3(BO3)4 microchip laser passively Q-switched by a Co2+:MgAl2 O4 crystal is reported.At a quasi-continuous-wave pump power of 20 W,a 1553 nm passively Q-switched laser with the repetition rate of 544 kHz,pulse duration of 8.3 ns,and pulse energy of 3.9 μJ was obtained.To the best of our knowledge,the 544 kHz is the highest reported value for the 1.5 μm passively Q-switched pulse laser.In the continuous-wave pumping experiment,the maximum repetition rate of 144 kHz with the pulse duration of 8.0 ns and pulse energy of 1.7 μJ was obtained at the incident pump power of 6.3 W.
基金supported by the National Natural Science Foundation of China (No.50802094)the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KJCX2-EW-H03-01)
文摘Diode-pumped acousto-optic Q-switched pulse laser at 1.5-1.6 μm is obtained in an Er3+:Yb3+:LuAl3 (BO3)4 crystal. Single-pulse laser operation with slope efficiency of 14% and threshold of approximately 100 mW is realized at an average absorbed pump power of 314 mW and repetition frequency of 20 kHz. Output pulse energy is 67 μJ. The effects of pulse repetition frequency, absorbed pump power, and duty cycle on the wavelength and pulse profile of the Q-switched Er3+:Yb3+:LuAl3(BO3)4 laser are also investigated.
