Intense 1-5 μm infrared emission from near-to mid-infrared was obtained from Ho3+/Yb3+codoped TeO2-ZnF2 oxyfluorotellurite glasses which were prepared by melt-quenching method under the 980 nm LD excitation,and the e...Intense 1-5 μm infrared emission from near-to mid-infrared was obtained from Ho3+/Yb3+codoped TeO2-ZnF2 oxyfluorotellurite glasses which were prepared by melt-quenching method under the 980 nm LD excitation,and the emission intensity can be enhanced with the increase of ZnF2 content.Judd-Ofelt analysis was used to evaluate the radiative transition parameters of the excited levels according to the absorption spectra.The stimulated emission cross section of 5 I6→5 I8(1.2 μm),5 I7→5 I8(2.0μm),5 I6→5 I7(2.85 μm) and 5 I5→5 I6(4.0 μm) transitions were calculated to reach 0.639 × 10-20,0.760 ×10-20,0.985×10 20 and 0.484 × 10-20 cm2,respectively.The energy transfer coefficients(CDA) are enhanced with the increase of ZnF2 content and phonon contribution ratios of phonon assisted energy transfer process between Ho3+ and Yb3+were figured out.Our results demonstrate that these TeO2-ZnF2 glasses,which possess good thermal stability and transparency,low phonon energy(about 600 cm-1),excellent near-and mid-infrared emission in the range of 1-5 μm wavelength,would be promising material for infrared optical fibers and infrared lasers.展开更多
Eu3＋-doped yttrium aluminum garnet （YAG） and Y2O3 composite phase nanoparticles were synthesized using a modified hydrothermal method. Sintering was performed at 800 ℃, which is considerably lower than the sinteri...Eu3＋-doped yttrium aluminum garnet （YAG） and Y2O3 composite phase nanoparticles were synthesized using a modified hydrothermal method. Sintering was performed at 800 ℃, which is considerably lower than the sintering temperature used in the conventional method, y3＋ in YAG and Y2O3 was partially substituted with Na＋ by adding NaNO3 into the solution during sample synthesis. The microstructures and phase transformation process were characterized through X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The obtained results verified that the addition of Na＋ promoted crystallinity and grain growth of the three phases, namely, Y2O3, Y4Al2O9, and Y3Al5O12. Highly efficient luminescence properties excited by 254 and 365 nm ultraviolet were achieved. In conclusion, the remarkable enhancement of the luminescence intensity with the addition of Na＋ should be attributed to grain growth and improvement of crystallinity.展开更多
基金Project supported by the National Natural Science Foundation of China (11574260)Hunan Provincial Graduate Research Innovation Project (CX2017B283)。
文摘Intense 1-5 μm infrared emission from near-to mid-infrared was obtained from Ho3+/Yb3+codoped TeO2-ZnF2 oxyfluorotellurite glasses which were prepared by melt-quenching method under the 980 nm LD excitation,and the emission intensity can be enhanced with the increase of ZnF2 content.Judd-Ofelt analysis was used to evaluate the radiative transition parameters of the excited levels according to the absorption spectra.The stimulated emission cross section of 5 I6→5 I8(1.2 μm),5 I7→5 I8(2.0μm),5 I6→5 I7(2.85 μm) and 5 I5→5 I6(4.0 μm) transitions were calculated to reach 0.639 × 10-20,0.760 ×10-20,0.985×10 20 and 0.484 × 10-20 cm2,respectively.The energy transfer coefficients(CDA) are enhanced with the increase of ZnF2 content and phonon contribution ratios of phonon assisted energy transfer process between Ho3+ and Yb3+were figured out.Our results demonstrate that these TeO2-ZnF2 glasses,which possess good thermal stability and transparency,low phonon energy(about 600 cm-1),excellent near-and mid-infrared emission in the range of 1-5 μm wavelength,would be promising material for infrared optical fibers and infrared lasers.
基金supported by the National Natural Scientific Foundation of China(No.10874144)the Scientific Foundation of Education,Department of Hunan Province,China(No. 06C818)
文摘Eu3＋-doped yttrium aluminum garnet （YAG） and Y2O3 composite phase nanoparticles were synthesized using a modified hydrothermal method. Sintering was performed at 800 ℃, which is considerably lower than the sintering temperature used in the conventional method, y3＋ in YAG and Y2O3 was partially substituted with Na＋ by adding NaNO3 into the solution during sample synthesis. The microstructures and phase transformation process were characterized through X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The obtained results verified that the addition of Na＋ promoted crystallinity and grain growth of the three phases, namely, Y2O3, Y4Al2O9, and Y3Al5O12. Highly efficient luminescence properties excited by 254 and 365 nm ultraviolet were achieved. In conclusion, the remarkable enhancement of the luminescence intensity with the addition of Na＋ should be attributed to grain growth and improvement of crystallinity.
