In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found ...In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.展开更多
A novel coordination polymer [Nd2（PDB）2（CH3COO）2（H2O）3] （H2PDB = pyridine3,4-dicarboxylic acid） has been synthesized by the reaction of Nd（CH3COO）3 with pyridine3,4-dicarboxylic acid under hydrothermal condi...A novel coordination polymer [Nd2（PDB）2（CH3COO）2（H2O）3] （H2PDB = pyridine3,4-dicarboxylic acid） has been synthesized by the reaction of Nd（CH3COO）3 with pyridine3,4-dicarboxylic acid under hydrothermal conditions. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the composition and crystal structure of the title complex which belongs to the triclinic system, space group P^-1 with a = 6.9409（14）, b = 7.5497（15）, c = 22.530（5）A, α = 84.79（3）, β = 88.15（3）, γ= 75.55（3）^o, C18H18N2O15Nd2, Mr = 790.82, Z = 2, V = 1138.5（4） A^3, Dc = 2.307 g/cm^3,μ = 4.593 mm^-1, -6≤h≤8, -5≤k ≤8, -26≤l≤ 26, F（000） = 760, Rint = 0.0298, R= 0.0314 and wR= 0.0695 （I〉 2σ（I））. Nd（1） and Nd（2） are linked into zigzag chains by carboxylate groups of acetate with interesting μ3-η^2：η^2 fashion. The zigzag chains are bridged by PDB to form a 2D framework, and a 3D supramolecular network is further constructed via π-π stacking.展开更多
A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-sw...A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.展开更多
The absorption and emission spectra of the YVO4 single crystal co-doped with 1 at.% Nd^3＋ and 1 at.% Yb^3＋ are investigated. The efficient Nd^3＋ → Yb^3＋ energy transfer and the back transfer （Yb^3＋ → Nd^3＋） ...The absorption and emission spectra of the YVO4 single crystal co-doped with 1 at.% Nd^3＋ and 1 at.% Yb^3＋ are investigated. The efficient Nd^3＋ → Yb^3＋ energy transfer and the back transfer （Yb^3＋ → Nd^3＋） are observed at room temperature. The fluorescence lifetime of the 4F3/2 level of Nd^3＋ in Nd,Yb：YVO4 is measured under 808 nm laser light excitation. The efficiency of Nd^3＋ → Yb^3＋ energy transfer in YVO4 is determined to be about 34%.展开更多
We present a laser-diode-pumped passively mode-locked femtosecond disordered crystal laser by using Nd：CaGdAI04 （Nd：CGA） as the gain medium. With a pair of SF6 prisms to control the dispersion compensation, laser ...We present a laser-diode-pumped passively mode-locked femtosecond disordered crystal laser by using Nd：CaGdAI04 （Nd：CGA） as the gain medium. With a pair of SF6 prisms to control the dispersion compensation, laser pulses as short as 850fs at 1079nm are obtained with a repetition rate of 124.6 MHz. The measured threshold pump power is 1.45 W. A maximum average output power of 122mW is obtained under the pump power of 5.9 W. These results show that Nd：CGA could be a promising laser medium for generating femtosecond ultrashort pulse at about 1 μm.展开更多
We have developed a Nd:YAP single crystal Aber laser with linearly polarised light output at 1.0795μm.The laser is 100μm in diameter and operated with a threshold of 6.65mW.The slope efficiency is 12.9%.
The effect of yttrium on the thermal stability and crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction （XRD）, differential scanning calorimeter （DSC）, and transmission...The effect of yttrium on the thermal stability and crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction （XRD）, differential scanning calorimeter （DSC）, and transmission electron microscopy （TEM）.The results indicated that the as-cast Nd60Fe20Al10Ni10-xYx（X=-0, 2） amorphous alloys were fabricated with some quenched-in crystals, which could be restrained by Y. With the effect of yttrium, both the crystallization temperature and exothermic peak shifted to higher temperatures, illustrating that the thermal stability could be improved. The addition of Y changed the crystallization process and final crystallization results. Moreover, the crystallites in the amorphous matrix became more homogeneous and smaller. Meanwhile, Y was useful for the passivation of oxygen in chemistry and restrained the negative effect of oxygen. The activation energies of the start of crystallization and peaking were 1.21 and 1.16 eV, respectively, according to the Kissinger equation.展开更多
The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in...The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30ns and the peak power of 1.75kW, at the incident pump power of 7.75W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7kHz and 680MHz, respectively.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 neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crysta...The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.展开更多
Amorphous （Nd,Pr）13Fe80Nb1B6 ribbons were crystallized at 670-730°C for 5-25 min to study the effects of isothermal crystallization on their behavior and magnetic properties. XRD results indicate that the isoth...Amorphous （Nd,Pr）13Fe80Nb1B6 ribbons were crystallized at 670-730°C for 5-25 min to study the effects of isothermal crystallization on their behavior and magnetic properties. XRD results indicate that the isothermal incubation time is 12, 5, and less than 5 min at 670, 700, and 730°C, respectively. High coercivities, with the maximum value of iHc = 1616 kA/m at 700°C for 19 min, measured by a physical property measurement system, are obtained in the crystallized ribbons. This is mainly attributed to the addition of Pr and Nb, because Pr2Fe14B has a higher anisotropic field than Nd2Fe14B, and Nb enriched in the grain boundary regions can not only reduce the exchange-coupling effects among hard grains, but also impede grain growth during the crystallization process. In addition, it should also be related to the characteristics of the furnace that the authors designed.展开更多
基金This project was supported by the Natural Science Foundation of Fujian Province (No. E0310031) ② Corresponding author. E-mail: tcy@fjirsm.ac.cn
文摘In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.
基金Project supported by the National Natural Science Foundation of China (No. 20671064)Foundation of Education Committee of Liaoning Province (No. 2005336)
文摘A novel coordination polymer [Nd2（PDB）2（CH3COO）2（H2O）3] （H2PDB = pyridine3,4-dicarboxylic acid） has been synthesized by the reaction of Nd（CH3COO）3 with pyridine3,4-dicarboxylic acid under hydrothermal conditions. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the composition and crystal structure of the title complex which belongs to the triclinic system, space group P^-1 with a = 6.9409（14）, b = 7.5497（15）, c = 22.530（5）A, α = 84.79（3）, β = 88.15（3）, γ= 75.55（3）^o, C18H18N2O15Nd2, Mr = 790.82, Z = 2, V = 1138.5（4） A^3, Dc = 2.307 g/cm^3,μ = 4.593 mm^-1, -6≤h≤8, -5≤k ≤8, -26≤l≤ 26, F（000） = 760, Rint = 0.0298, R= 0.0314 and wR= 0.0695 （I〉 2σ（I））. Nd（1） and Nd（2） are linked into zigzag chains by carboxylate groups of acetate with interesting μ3-η^2：η^2 fashion. The zigzag chains are bridged by PDB to form a 2D framework, and a 3D supramolecular network is further constructed via π-π stacking.
基金Supported by the Science and Technology Department Project of Jilin Province under Grant Nos 2010PT and 20100355.
文摘A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.
基金Project supported by the National Natured Science Foundation of China （Grant No 60438020）.
文摘The absorption and emission spectra of the YVO4 single crystal co-doped with 1 at.% Nd^3＋ and 1 at.% Yb^3＋ are investigated. The efficient Nd^3＋ → Yb^3＋ energy transfer and the back transfer （Yb^3＋ → Nd^3＋） are observed at room temperature. The fluorescence lifetime of the 4F3/2 level of Nd^3＋ in Nd,Yb：YVO4 is measured under 808 nm laser light excitation. The efficiency of Nd^3＋ → Yb^3＋ energy transfer in YVO4 is determined to be about 34%.
基金Supported by the National Key Basic Research Program of China under Grant No 2013CB922402the International Joint Research Program,and the National Natural Science Foundation of China under Grant Nos 61210017 and 11434016
文摘We present a laser-diode-pumped passively mode-locked femtosecond disordered crystal laser by using Nd：CaGdAI04 （Nd：CGA） as the gain medium. With a pair of SF6 prisms to control the dispersion compensation, laser pulses as short as 850fs at 1079nm are obtained with a repetition rate of 124.6 MHz. The measured threshold pump power is 1.45 W. A maximum average output power of 122mW is obtained under the pump power of 5.9 W. These results show that Nd：CGA could be a promising laser medium for generating femtosecond ultrashort pulse at about 1 μm.
文摘We have developed a Nd:YAP single crystal Aber laser with linearly polarised light output at 1.0795μm.The laser is 100μm in diameter and operated with a threshold of 6.65mW.The slope efficiency is 12.9%.
基金the National Natural Science Foundation of China (50571052)
文摘The effect of yttrium on the thermal stability and crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction （XRD）, differential scanning calorimeter （DSC）, and transmission electron microscopy （TEM）.The results indicated that the as-cast Nd60Fe20Al10Ni10-xYx（X=-0, 2） amorphous alloys were fabricated with some quenched-in crystals, which could be restrained by Y. With the effect of yttrium, both the crystallization temperature and exothermic peak shifted to higher temperatures, illustrating that the thermal stability could be improved. The addition of Y changed the crystallization process and final crystallization results. Moreover, the crystallites in the amorphous matrix became more homogeneous and smaller. Meanwhile, Y was useful for the passivation of oxygen in chemistry and restrained the negative effect of oxygen. The activation energies of the start of crystallization and peaking were 1.21 and 1.16 eV, respectively, according to the Kissinger equation.
文摘The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30ns and the peak power of 1.75kW, at the incident pump power of 7.75W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7kHz and 680MHz, respectively.
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.
文摘The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.
基金supported by the National Natural Science Foundation of China (No. 50744014)the National Basic Research Foundation (No. 2004CCA04000)+3 种基金Science and Technology Department of Zhejiang Province (Nos. 2008C21046 and 2008C11086-1)the Natural Science Foundation of Zhejiang Province,China (No. Y406389)the Research and Development Program of Ningbo Bureau of Science and Technology (No. 2006B100054)K.C.Wong Magna Found in Ningbo University
文摘Amorphous （Nd,Pr）13Fe80Nb1B6 ribbons were crystallized at 670-730°C for 5-25 min to study the effects of isothermal crystallization on their behavior and magnetic properties. XRD results indicate that the isothermal incubation time is 12, 5, and less than 5 min at 670, 700, and 730°C, respectively. High coercivities, with the maximum value of iHc = 1616 kA/m at 700°C for 19 min, measured by a physical property measurement system, are obtained in the crystallized ribbons. This is mainly attributed to the addition of Pr and Nb, because Pr2Fe14B has a higher anisotropic field than Nd2Fe14B, and Nb enriched in the grain boundary regions can not only reduce the exchange-coupling effects among hard grains, but also impede grain growth during the crystallization process. In addition, it should also be related to the characteristics of the furnace that the authors designed.
