The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spect...The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spectrum,emission spectrum,Judd-Ofelt analysis and fluorescence decay curve at room temperature were discussed.The fluorescence lifetime of Pr:CaF_(2)-YF_(3)crystal was 45.46µs,and theσem·τof ^(3)P0→^(3)H_(6) and ^(3)P0→^(3)F_(2) transitions were calculated to be 80.92×10^(−20) cm^(2)·µs and 388.7×10^(−20) cm^(2)·µs,respectively.The FWHMs are 20.1 nm and 6.8 nm,which are higher than those of Pr:LiYF_(4),Pr:LiLuF_(4),Pr:LiGdF_(4) and Pr:BaY_(2)F_(8) crystals.The results show that the Pr:CaF_(2)-YF_(3)crystal is expected to achieve 605 nm orange light and 642 nm red light laser operation.展开更多
对Nd,Y:CaF_2晶体作为激光放大器的增益介质进行了报道.研制了一台采用激光二极管面阵五向水平侧面抽运Ф5 mm×70 mm Nd,Y:CaF_2的激光放大器,对其进行了实验研究.测量了Nd,Y:CaF_2晶体的吸收谱、发射谱、以及放大器的荧光分布.在...对Nd,Y:CaF_2晶体作为激光放大器的增益介质进行了报道.研制了一台采用激光二极管面阵五向水平侧面抽运Ф5 mm×70 mm Nd,Y:CaF_2的激光放大器,对其进行了实验研究.测量了Nd,Y:CaF_2晶体的吸收谱、发射谱、以及放大器的荧光分布.在相同的抽运功率下,测量了Nd,Y:CaF_2与Nd:Glass放大器分别工作在10 Hz和1 Hz重复频率时的小信号增益,在抽运功率为9.63 kW时,Nd,Y:CaF_2放大器的小信号增益达6.12,为Nd:Glass的1.5倍.与Nd:Glass相比,Nd,Y:CaF_2晶体的重复工作频率不仅大大提高,而且增益性能也更强.测量了种子光和经Nd,Y:CaF_2放大器后的光谱,能量放大前后光谱几乎无变化.展开更多
This paper reports the growth, X-ray diffraction and spectroscopy of Nd3＋：Sr3Gd2（BO3）4 crystal. A Nd3＋：Sr3Gd2（BO3）4 crystal with dimensions of φ20 × 45 mm3 has been grown by the Czochralski method. Nd3＋...This paper reports the growth, X-ray diffraction and spectroscopy of Nd3＋：Sr3Gd2（BO3）4 crystal. A Nd3＋：Sr3Gd2（BO3）4 crystal with dimensions of φ20 × 45 mm3 has been grown by the Czochralski method. Nd3＋：Sr3Gd2（BO3）4 crystal belongs to the orthorhombic system, space group Pnma （D2h） with a = 0.7401, b = 1.604 and c = 0.8755 nm. The absorption and emission spectra of Nd3＋：Sr3Gd2（BO3）4 were investigated. The absorption cross section oa is 3.11 × 10^-20cm2 at 808 nm. The absorption transition at 808 nm has an FWHM of 14 nm. The luminescence lifetime τf is 51.7 μs. The emission cross section oc at 1064 nm wavelength is 1.09 × 10^-19 cm2.展开更多
The Nd^3＋：LiGd（WO4） 2 crystal with dimensions of 25mm×28mm×16mm was grown by the top-seeded solution growth method from the 60 mol% Li2W2O7 flux. LiGd（WO4） 2 crystallizes in the tetragonal system with ...The Nd^3＋：LiGd（WO4） 2 crystal with dimensions of 25mm×28mm×16mm was grown by the top-seeded solution growth method from the 60 mol% Li2W2O7 flux. LiGd（WO4） 2 crystallizes in the tetragonal system with space group I41/a（C4h^6） and cell parameters： a = 5.1986 and c = 11.2652A. The hardness is about 5.0 Mohs＇ scale. The specific heat is 0.40 J·g^-1·K^-1 at 50 oC. The thermal expansion coefficients for a-and c-axes are 1.314×10^-5 and 2.052×10^-5 K^-1,respectively. The room-temperature polarized absorption and emission spectra and the fluorescence decay curve was measured. The parameters of oscillator strengths,the spontaneous transition probabilities,the fluorescence branching ratios,the radiative lifetimes,and the emission cross sections have been investigated based on Judd-Ofelt theory and Füchtbauer-Ladenburg method. The absorption cross-section is 5.19×10^-20 cm^2 at 805 nm for π-polarization and its line width is 15 nm; the emission cross section is 1.726×10^-19 cm^2 at 1060.5 nm for π-polarization. The fluorescence and radiative lifetimes are 86 and 158 μs,respectively. The fluorescence quantum efficiency is 54.43%.展开更多
X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd（FexMn1-x）2Si2 （0≤x 〈 1） compounds which crystallize in a ThCr2Si2-type structure with the space group 14/...X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd（FexMn1-x）2Si2 （0≤x 〈 1） compounds which crystallize in a ThCr2Si2-type structure with the space group 14/mmm. The field-cooled temperature dependence of the magnetization curves shows that, at low temperatures, NdFe2Si2 is antiferromagnetic, while the other compounds show ferromagnetic behaviour. The substitution of Fe for Mn leads to a decrease in lattice parameters a, c and unit-cell volume V. The Curie temperature of the compounds first increases, reaches a maximum around x=0.7, then decreases with Fe content. However, the saturation magnetization decreases monotonically with increasing Fe content. This Fe concentration dependent magnetization of Nd（FexMn1-x）2Si2 compounds can be well explained by taking into account the complex effect on magnetic properties due to the substitution of Mn by Fe. The temperature＇s square dependence on electrical resistivity indicates that the curve of Nd（Fe0.6Mn0.4）2Si2 has a quasi-linear character above its Curie temperature, which is typical of simple metals.展开更多
Nd:NaBi(WO_4)_2 crystals (Nd:NBW) were grown by Czochralski method. The pulling rate is 0.3 mm·h (-1),and the rotational speed of Nd:NBW crystal is 2 r·min (-1). The components of this single crystal were de...Nd:NaBi(WO_4)_2 crystals (Nd:NBW) were grown by Czochralski method. The pulling rate is 0.3 mm·h (-1),and the rotational speed of Nd:NBW crystal is 2 r·min (-1). The components of this single crystal were determined by X-ray diffractions,and its corresponding properties were described from thermal gravity and differential thermal analysis experiments. The absorption cross-sections were calculated. The emission band of Nd:NBW crystal was obtained from its luminous spectrum.展开更多
The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20...The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20 cm2 and ?6 = 3.1189×10-20 cm2; the radiative lifetime is 123 μs; the quantum efficiency is equal to 64.55%; and β1 = 0.5498, β2 = 0.3943, β3 = 0.0551 and β4 = 0.0027 for the fluorescence branch ratios.展开更多
Nd^3＋ doped KLa（MoO4）2 single crystal with the size up to Ф25 × 40 mm^3 was grown by the Czochralski technique. The absorption and luminescence spectra of trivalent neodymium in KLa（MoO4）2 crystal were inve...Nd^3＋ doped KLa（MoO4）2 single crystal with the size up to Ф25 × 40 mm^3 was grown by the Czochralski technique. The absorption and luminescence spectra of trivalent neodymium in KLa（MoO4）2 crystal were investigated at room temperature. The absorption and emission cross 10-20 sections are 3.02 ×10^-20 cm^2 at 808 nm and 20.01 × 10^-2 cm^2 at 1061 nm, respectively. The fluorescence lifetime is 164μs at room temperature.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61805177,61861136007,and 61621001).
文摘The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spectrum,emission spectrum,Judd-Ofelt analysis and fluorescence decay curve at room temperature were discussed.The fluorescence lifetime of Pr:CaF_(2)-YF_(3)crystal was 45.46µs,and theσem·τof ^(3)P0→^(3)H_(6) and ^(3)P0→^(3)F_(2) transitions were calculated to be 80.92×10^(−20) cm^(2)·µs and 388.7×10^(−20) cm^(2)·µs,respectively.The FWHMs are 20.1 nm and 6.8 nm,which are higher than those of Pr:LiYF_(4),Pr:LiLuF_(4),Pr:LiGdF_(4) and Pr:BaY_(2)F_(8) crystals.The results show that the Pr:CaF_(2)-YF_(3)crystal is expected to achieve 605 nm orange light and 642 nm red light laser operation.
文摘This paper reports the growth, X-ray diffraction and spectroscopy of Nd3＋：Sr3Gd2（BO3）4 crystal. A Nd3＋：Sr3Gd2（BO3）4 crystal with dimensions of φ20 × 45 mm3 has been grown by the Czochralski method. Nd3＋：Sr3Gd2（BO3）4 crystal belongs to the orthorhombic system, space group Pnma （D2h） with a = 0.7401, b = 1.604 and c = 0.8755 nm. The absorption and emission spectra of Nd3＋：Sr3Gd2（BO3）4 were investigated. The absorption cross section oa is 3.11 × 10^-20cm2 at 808 nm. The absorption transition at 808 nm has an FWHM of 14 nm. The luminescence lifetime τf is 51.7 μs. The emission cross section oc at 1064 nm wavelength is 1.09 × 10^-19 cm2.
基金Supported by the National Natural Science Foundation of China (No.60808033)Natural Science Foundation of Jiangxi Province (No.2008GZW0012)
文摘The Nd^3＋：LiGd（WO4） 2 crystal with dimensions of 25mm×28mm×16mm was grown by the top-seeded solution growth method from the 60 mol% Li2W2O7 flux. LiGd（WO4） 2 crystallizes in the tetragonal system with space group I41/a（C4h^6） and cell parameters： a = 5.1986 and c = 11.2652A. The hardness is about 5.0 Mohs＇ scale. The specific heat is 0.40 J·g^-1·K^-1 at 50 oC. The thermal expansion coefficients for a-and c-axes are 1.314×10^-5 and 2.052×10^-5 K^-1,respectively. The room-temperature polarized absorption and emission spectra and the fluorescence decay curve was measured. The parameters of oscillator strengths,the spontaneous transition probabilities,the fluorescence branching ratios,the radiative lifetimes,and the emission cross sections have been investigated based on Judd-Ofelt theory and Füchtbauer-Ladenburg method. The absorption cross-section is 5.19×10^-20 cm^2 at 805 nm for π-polarization and its line width is 15 nm; the emission cross section is 1.726×10^-19 cm^2 at 1060.5 nm for π-polarization. The fluorescence and radiative lifetimes are 86 and 158 μs,respectively. The fluorescence quantum efficiency is 54.43%.
基金Project supported by the National Basic Research Program of China (Grant No 2006CB601101)
文摘X-ray powder diffraction, resistivity and magnetization studies have been performed on polycrystalline Nd（FexMn1-x）2Si2 （0≤x 〈 1） compounds which crystallize in a ThCr2Si2-type structure with the space group 14/mmm. The field-cooled temperature dependence of the magnetization curves shows that, at low temperatures, NdFe2Si2 is antiferromagnetic, while the other compounds show ferromagnetic behaviour. The substitution of Fe for Mn leads to a decrease in lattice parameters a, c and unit-cell volume V. The Curie temperature of the compounds first increases, reaches a maximum around x=0.7, then decreases with Fe content. However, the saturation magnetization decreases monotonically with increasing Fe content. This Fe concentration dependent magnetization of Nd（FexMn1-x）2Si2 compounds can be well explained by taking into account the complex effect on magnetic properties due to the substitution of Mn by Fe. The temperature＇s square dependence on electrical resistivity indicates that the curve of Nd（Fe0.6Mn0.4）2Si2 has a quasi-linear character above its Curie temperature, which is typical of simple metals.
文摘Nd:NaBi(WO_4)_2 crystals (Nd:NBW) were grown by Czochralski method. The pulling rate is 0.3 mm·h (-1),and the rotational speed of Nd:NBW crystal is 2 r·min (-1). The components of this single crystal were determined by X-ray diffractions,and its corresponding properties were described from thermal gravity and differential thermal analysis experiments. The absorption cross-sections were calculated. The emission band of Nd:NBW crystal was obtained from its luminous spectrum.
基金This work was supported by the National Natural Science Foundation of China (50272066) and Key Project of Science and Technology of Fujian Province (2001F004)
文摘The spectral parameters of Nd3+ ions in Nd3+:Klu(WO4)2 crystal were calculated based on Judd-Ofelt theory and obtained as follows: for the oscillator strengths ?λ: ?2 = 7.5029×10-20 cm2, ?4 = 7.1837×10-20 cm2 and ?6 = 3.1189×10-20 cm2; the radiative lifetime is 123 μs; the quantum efficiency is equal to 64.55%; and β1 = 0.5498, β2 = 0.3943, β3 = 0.0551 and β4 = 0.0027 for the fluorescence branch ratios.
基金This work was supported by the National Natural Science Foundation of China (50272066) and Key Project of Science and Technology of Fujian (2001H107)
文摘Nd^3＋ doped KLa（MoO4）2 single crystal with the size up to Ф25 × 40 mm^3 was grown by the Czochralski technique. The absorption and luminescence spectra of trivalent neodymium in KLa（MoO4）2 crystal were investigated at room temperature. The absorption and emission cross 10-20 sections are 3.02 ×10^-20 cm^2 at 808 nm and 20.01 × 10^-2 cm^2 at 1061 nm, respectively. The fluorescence lifetime is 164μs at room temperature.
基金This work supported by the Natural Science Foundation of Fujian Province (No.60378031)Key Project of Science andTechnology of Fujian Province (No.2001F004).
