Crystal Growth and Spectral Properties of Yb3+:KY(WO4)2

Laser crystal Yb∶KYW was grown by the Kyropoulos method. A grown crystal was identified as β-Yb∶KYW by XRD. By TG-DTA the melting point and transition point of the crystal are 1045 and 1010 ℃, respectively. Infrared spectrum and Raman spectrum were measured, and the vibrational frequencies of infrared and Raman active modes for Yb∶KYW crystal were assigned. Absorption spectrum of Yb∶KYW shows that there are two intensive absorption peaks at 940 and 980 nm, respectively, and the absorption cross section is 1.34×10-19 cm2 at chief peak of 980 nm. There exist three intensive emission peaks in Yb∶KYW at 990, 1010 and 1030 nm, respectively, and the emission line width of the chief peak 1030 nm runs up to 16 nm. It was calculated that the peak emission cross section is 3.1×10-20 cm2 at 1030 nm.     

Growth and characterization of Nd:Sr0.95Ba0.05WO4 single crystal

Synthesis of polycrystalline Nd:Sr0.95Ba0.05WO4 by means of liquid- and solid-phase reaction was reported. X-ray powder diffraction results showed that the as-grown Sr0.95Ba0.05WO4 and Nd: Sr0.95Ba0.05WO4 single crystals belonged to tetragonal system and I41/a space group. Transparent Nd: Sr0.95Ba0.05WO4 single crystal could be obtained along c-axis by Czochralski method from the synthesized polycrystalline material. As the transmittance of Sr0.95Ba.005WO4 single crystal could reach 80%, Nd3+ ion was adopted to be doped into the single crystal. Spontaneous Raman spectrums of polycrystalline material and single crystal were measured by RERKZN-ELMER2000 and JY-HR800. By using X-ray fluorescence method, the effective segregation coefficients of Nd, Ba, Sr, and W elements in Sr0.95Ba.005WO4 single crystal were estimated as 0.844 (0.745), 0.44, 1.09, and 0.95, respectively. The segregation coefficients of Nd in Sr0.95Ba0.05WO4 were higher than that in BaWO4, and this is as better as a Raman laser crystal.     

Study on Growth and Spectra Properties of Nd: GGG Crystal

The laser crystal Nd GGG was grown by Cz method. The optimum processing parameter is that the pulling rate is 2~4mm·h-1, the rotation rate is 20~40 r·min-1 and the cooling rate is 20℃. The absorption and fluorescence spectra of Nd GGG were measured. The main absorption peak of Nd GGG is at 808 nm and the fluorescence emission peak is at 9430cm-1, corresponding to 4F3/2-4I11/2 emission band of Nd3 ions.     

Growth of Yb∶YAB Crystal and Its Laser Performance

Ｓｅｌｆ ｆｒｅｑｕｅｎｃｙ ｄｏｕｂｌｉｎｇｓｉｎｇｌｅｃｒｙｓｔａｌｓａｒｅｏｎｅｋｉｎｄｏｆｔｈｅｐｏｌｙｆｕｎｃｔｉｏｎｍａｔｅｒｉａｌｓ .Ｔｈｅｙｐｏｓｓｅｓｓｂｏｔｈｌａｓｅｒｃｒｙｓｔａｌｐｒｏｐｅｒｔｉｅｓａｎｄｎｏｎ ｌｉｎｅａｒｃｒｙｓｔａｌｐｒｏｐｅｒｔｉｅｓ .Ｔｈｅｓｏｌｉｄｓｔａｔｅｌａｓｅｒｓｆａｂｒｉｃａｔｅｄｂｙｔｈｅｓｅｍａｔｅｒｉａｌｓｈａｖｅｓｉｍｐｌｅｓｔｒｕｃ ｔｕｒｅａｎｄａｒｅｅａｓｙｔｏｏｐｅｒａｔｅ .Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐ ｍｅｎｔｏｆｄｉｏｄ…     

Growth,structure and spectral characteristics of KEr_(0.1)Yb_(0.9)(WO_4)_2 laser crystal

The 10 at.% Er3+-doped KYb(WO4)2(KEr0.1Yb0.9(WO4)2) laser crystal with dimensions up to 25 mm×15 mm×10 mm was grown by the Kyropoulos method.The crystal structure was identified as β-KEr0.1Yb0.9(WO4)2 by XRD analysis.Through TG-DTA curves,the melting point and transition point of the crystal were determined to be 1058 and 1031 °C,respectively.Infrared spectrum and Raman spectrum were measured,and the vibration frequencies of infrared and Raman active modes for the crystal were assigned.The absorption cross section is 3.1×10-20 cm2 at chief peak of 981 nm with the absorption line width of 26 nm.Based on the Judd-Ofelt theory,the intensity parameters ?λ(λ=2,4,6) calculated were:?2=16.34×10-20 cm2,?4=4.18×10-20 cm2,and ?6=1.26×10-20 cm2.There was a strong emission peak near 1533 nm and the emission line width at the main peak at 1533 nm run up to 55 nm with the emission cross section of 3.47×10-20 cm2 .These optical parameters indicated the potential of this crystal used as an excellent laser material for 1540 nm nearby human-eye safe.     

Paramagnetic Anisotropy of CdGd2(WO4)4-δ Single Crystal

CdGd2(WO4)4-δ single crystal was grown using the Czochralski's method. The crystal structure was tetragonal scheelite with lattice parameters a=b=0.5203 nm and c=1.1359 nm. There were vacancies of (WO4)2-, therefore, there were some Gd2+ ions. Langevin paramagnetism and anisotropy were observed from the σ-T curves at room temperature. The susceptibility χ// was 3.5018×10-3, and χ⊥ was 3.4403×10-2. The anisotropy was also observed in the electron spin resonance (ESR) experiments. The anisotropic Landé factors were g//=2.1333 and g⊥=2.8411. The direction of easy magnetization was in the a-b plane. Anisotropic paramagnetic Curie constants C// and C⊥ were not only related to macroscopic σ that was observed through the experiment, but were also related to J⊥ and J//, which were the microscopic quantum numbers of the Gd2+ and Gd3+ ions. Based on the detailed analyses, the proportion of 36.8% of Gd3+ ions to 63.2% of Gd2+ ions in the Gd ions of the CdGd2(WO4)4-δ crystal was calculated, and δ was 0.638 in the single crystal.     

Synthesis and Spectral Properties of Nd3+:Gd3Ga5O12 Nanopowder for Transparent Laser Ceramics

Nd3 :Gd3Ga5O12 (Nd:GGG) nanopowder for transparent laser ceramics was synthesized using sol-gel method. XRD, SEM, and fluorescence spectrum were used to study the properties of Nd3 :Gd3Ga5O12 nanopowder. XRD patterns of samples show that it has a cubic structure. Meanwhile, pure Nd:GGG crystals were obtained at 1000 ℃ for 12 h. SEM photographs show that dispersed, uniform, ball-like Nd:GGG nanopowder is obtained. Both XRD and SEM results show that the crystallization degree and the grain size increase with the increase in calcining temperature. Analysis of fluorescence spectrum shows that fluorescence emission occurs at 1062.7 nm, which is the result of Nd3 (4F3/2→4I11/2) transition. Homogenous Nd:GGG nanopowder with a small grain size synthesized using the sol-gel method is favorable for sintering the transparent ceramic, which proves that the nanopowder obtained is suitable as a precursor for preparing GGG transparent ceramics.     

Growth and Characteristic of YbAl3(BO3)4 Crystal

YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the double borates with a trigonal structure. The space group is R32 and its unit cell constants were measured to be a=0.92965 nm, c=0.72129 nm, V=0.53673 nm3, Z=3. The transmittance spectra were measured. The cut-off of YbAl3(BO3)4 crystal is 216 nm, and there are two absorption peaks located at 940 and 975 nm from 190 nm to 2600 nm. The thermal properties of YbAl3(BO3)4 crystal were studied for the first time. The average thermal expansion coefficients were determined to be 2×10-6/℃, 9.5×10-6/℃ along a- and c- direction. The specific heat of YbAl3(BO3)4 crystal was measured to be 0.6695 J·(g·℃)-1 at room temperature. All results indicate that the YbAl3(BO3)4 crystal is an excellent stoichioimetric laser material.     

Growth and Spectral Properties of Crystal Er3+:Y0.5Gd0.5VO4

Er3 :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er3 ions in the crystal was measured by the ICP method. The absorption and emission spectra were also measured. On the basis of the spectra, the absorption cross-sections, emission spectrum FWHM and fluorescence lifetime of the crystal were calculated. From the properties mentioned above.     

Crystal Growth and Spectral Properties of Yb^3＋ ：KY（WO4 ）2

Laser crystal Yb:KYW was grown by the Kyropoulos method. A grown crystal was identified as β-Yb:KYW by XRD. By TG-DTA the melting point and transition point of the crystal are 1045 and 1010 °C, respectively. Infrared spectrum and Raman spectrum were measured, and the vibrational frequencies of infrared and Raman active modes for Yb:KYW crystal were assigned. Absorption spectrum of Yb:KYW shows that there are two intensive absorption peaks at 940 and 980 nm, respectively, and the absorption cross section is 1.34 × 10⁻¹⁹ cm² at chief peak of 980 nm. There exist three intensive emission peaks in Yb:KYW at 990, 1010 and 1030 nm, respectively, and the emission line width of the chief peak 1030 nm runs up to 16 nm. It was calculated that the peak emission cross section is 3.1 × 10⁻²⁰ cm² at 1030 nm.     

Nd3+ Doped Silicate Glass Photonic Crystal Fiber with Random Hole Distributions

The fabrication of one kind of large core area Nd3 doped silicate glass photonic crystal fiber, and demonstration of the fiber's waveguidence properties were reported. This fiber owns a random air hole distribution in the cladding. The measured minimum loss of this kind of fiber is 10 dB·m-1 at 660 nm. These fibers can sustain only a single mode at least over wavelength ranging from 660 nm to 980 nm.     

Synthesis and Crystal Structure of a 4f-3d Complex [La(DMF)_6(H_2O)_3][Cr(CN)_6]·2H_2O

Ｒｅｃｅｎｔｌｙ ,ｔｈｅｒｅｈａｓｂｅｅｎｃｏｎｓｉｄｅｒａｂｌｅｉｎ ｔｅｒｅｓｔｉｎｌａｎｔｈａｎｉｄｅ(Ⅲ )ｈｅｘａｃｙａｎｏｆｅｒｒａｔｅｓａｎｄｔｈｅａｎａｌｏｇｏｕｓｃｏｂａｌｔ(Ⅲ )ａｓｗｅｌｌａｓｃｈｒｏｍｉｕｍ(Ⅲ )ｃｏｍｐｌｅｘｅｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｓｃａｔａｌｙｔｉｃ ,ｓｅｍｉｃｏｎｄｕｃｔｉｖｅ ,ａｎｄｍａｇｎｅｔｉｃｍａｔｅ ｒｉａｌｓ[1～ 4] .Ｆｏｒｅｘａｍｐｌｅ ,ｍａｇｎｅｔｉｃｓｔｕｄｉｅｓｏｎａｓｅｒｉｅｓｏｆｔｈｒｅｅ ｄｉｍｅｎｓｉｏ…     

Mechanisms of Fluorescence Quenching of Pr^3＋-Doped PbWO4 Crystal

Fluorescence decay curves of the ^3P0 and ^1D2 manifolds in Pr^3＋ doped PbWO4 crystal were measured at room temperature and fluorescence lifetimes of both manifolds were estimated. Combining with the radiative lifetimes of the manifolds calculated on the basis of the modified J-O theory, the main mechanisms for the fluorescence quenching of the manifolds were analyzed. The multi-phonon relaxation and the cross-relaxation energy transfer are the major reasons for the fluorescence quenching of the ^3P0 and ^1D2 manifolds, respectively. The Inokuti-Hirayama model was used to analyze the fluorescence decay curve of the ^1D2 manifold and the cross-relaxation of dlpole-dipole interaction was confirmed. Consequently, the ^3p0 manifold is more favorable as an upper laser level than the ^1D2 manifold.     

Upconversion luminescence of KGd（MoO_4）_2：Er~（3＋）,Yb~（3＋） powder prepared by Pechini method

Er3+ doped potassium gadolinium molybdate (KGM) phosphor with sensitizer Yb3+ ion was synthesized by the Pechini method using citric acid and ethylene glycol. The crystallization processes of the phosphor precursors were characterized by X-ray diffraction (XRD) and thermogravimetry-differential scanning calorimetry (TG-DSC), which indicated that ultrafine uniform crystallites of KGM:Er,Yb were obtained by sintering the precursors at above 650 ℃ for 5 h. Upconversion luminescence (UL) spectra of the samples ...     

Spectral Parameters of Nd~(3+)∶Sr_6YSc(BO_3)_6

Ｉｎｒｅｃｅｎｔｙｅａｒｓ ,ｒｅｓｅａｒｃｈｏｎｎｅｗｍａｔｅｒｉａｌｓｗｉｔｈｉｍｐｒｏｖｅｄｓｐｅｃｔｒａｌｐｒｏｐｅｒｔｉｅｓｆｏｒｄｉｏｄｅｐｕｍｐｉｎｇｉｓｏｆｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔ ,ｓｉｎｃｅｄｉｏｄｅ ｌａｓｅｒｐｕｍｐｅｄｓｏｌｉｄ ｓｔａｔｅｌａｓｅｒｓｈａｖｅｂｅｅｎｆｏｕｎｄｉｎａｗｉｄｅｖａｒｉｅｔｙｏｆａｐｐｌｉ ｃａｔｉｏｎｓｉｎｔｈｅｆｉｅｌｄｓｏｆｍｉｌｉｔａｒｙ ,ｉｎｄｕｓｔｒｙ ,ｍｅｄｉｃａｌｔｒｅａｔｍｅｎｔａｎｄｓｃｉｅｎｔｉｆｉｃｒｅｓｅａｒ…     

Effect of Nd^3＋ on Photosynthesis of Spinach

The effect of Nd^3 on the photosynthesis and the growth of spinach was studied. The results show that Nd^3 improves the growth of spinach and increases chlorophyll content and photosynthetic rate. UV-Vis spectrum indicates that the Soret band of chl-a in spinach with NdCl3 treatment is blue shifted by 2 nm, and the Q band is red shifted by 1 nm, and the ratio of Soret band intensity and Q band intensity increases. FT-IR spectra show that the peak of porphyrin ring in chl-a of spinach with NdCl3 treatment is widened, suggesting that the formation of Nd^3 -chl-a. Treated by NdCl3, the fluorescence emission peak of PSⅡ in spinach leaves is blue shifted by 12 nm and the intensity declines obviously, indicating that Nd^3 is bound to the PSⅡ protein-pigment complex and the electron transfer rate increases.     

Synthesis and Crystal Structure of a Neodymium Ionic Associate [Nd(dmso)_7Cl][Bph_4]_2

Ｓｕｌｆｏｘｉｄｅｉｓｋｎｏｗｎｔｏｆｏｒｍｃｏｏｒｄｉｎａｔｉｏｎｃｏｍｐｏｕｎｄｓｗｉｔｈｌａｎｔｈａｎｉｄｅｓａｎｄｔｈｅｉｒｓｙｎｔｈｅｓｅｓ,ｐｒｏｐｅｒｔｉｅｓａｎｄｖａｒｉｏｕｓｐｈｙｓｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄ[1～7].Ｈｏｗｅｖｅｒ,ｔｈｅｒｅａｒｅｓｏｍａｎｙｄｉｆｆｉｃｕｌｔｉｅｓｉｎｐｒｅｐａｒｉｎｇｔｈｉｓｋｉｎｄｏｆｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｂｅｃａｕｓｅｔｈｅｉｏｎｓｕｓｅｄａｒｅａｌｍｏｓｔｔｈｏｓｅｗｈｉｃｈｈ…     

Synthesis, Characterization and Crystal Structure of Neutral Homoleptic Lanthanide Amide Yb（NPh2）3（THF）2

A neutral homoleptic lanthanide amide Yb(NPh2)3(THF)2 was obtained by reaction of anhydrous YbCl3 with LiNPh2 in THF. The product was characterized by elemental analysis, infrared spectrum and X-ray crystallographic analysis. The crystal data are monoclinic, P21/n space group, a=1.2052(2) nm, b=1.9369(3) nm, c=1.6523(2) nm, β=92.79(1)°, V=3.8524(9) nm3, Z=4, Dc=1.417 g*cm-3, μ=24.67 cm-1 (Mo Kα), F(000)=1668, R=0.036, Rw=0.039. The central metal ytterbium is coordinated by three terminal NPh2 groups and two THF molecules to form a five-coordinate distorted trigonal bipyramid. The mean Yb-N bond length is 0.2219(6) nm.     

Growth and characterization of ferroelectric Tb2（MoO4）3 crystal

By using Zb4O7 and MoO4 as starting materials, ferroelectric Tb2(MoO4)3 crystal was grown by the Czochralski method. The as-grown crystal was pale green color, transparent and crack-free. X-ray powder diffraction (XRPD), transmission spectrum, dielectric con-stant and polarization-electric field (P-E) hysteresis loop measurements were performed to characterize the crystal. The XRPD confirmed the as-grown crystal to be Tb2(MoO4)3. The transmission spectrum of the crystal showed that its transmittance in the entire visible and most near-infrared region was more than 70% except for an absorption peak around 486 nm. Obvious dielectric anomaly could be observed at low frequencies with increasing temperature through the dielectric constant measurement and the Curie temperature of Tb2(MoO4)3 crystal was determined to be 162.3℃. The unsaturated P-E hysteresis loops indicated that it was difficult for the ferroelectric domains in Tb2(MoO4)3 crystal to array regularly with repeated switching of the electric field.