Properties Of Yb Research Articles

Rare-Earth-doped Laser Materials: Spectroscopy and Laser Properties

ABSTRACTTrivalent rare earth ions in crystalline or fiber hosts are among the most successful of laser materials, but new dopant-host combinations and more detailed understanding of existing materials continue to be needed. This paper presents a few examples from the work of our team at the Army Research Laboratory, highlighting the interrelation between spectroscopic properties and laser behavior. It focuses on bulk solids, though rare-earth-doped fiber lasers are also extremely important. One system discussed is Nd:YAG, particularly concentration quenching in heavily doped ceramic YAG. Spectroscopic properties of Yb:Y2O3 and Yb:Sc2O3 help to elucidate their laser performance. Spectra indicate that Er:YAG is more promising than Er:Sc2O3 for room temperature laser operation, but that the reverse is true for operation at and somewhat above liquid nitrogen temperature.

Synthesis and properties of Yb: Sc 2O 3 transparent ceramics

Yb: Sc 2O 3 transparent ceramics were fabricated by solid-state reaction and vacuum sintering method. CaO was added as sintering aids by a high energy ball milling. Transparent nearly-fully dense samples were obtained after 1840 °C sintering. Using transmitted-light microscope we get the grain sizes are more than 100 μm. Using spectrophotometer we get the absorption coefficient centered at 975 nm was 2.65 cm −1. The phosphorescence spectra showed that the line-widths (FWHM) at 975 and 1041 nm were about 4 and 10 nm and the lifetime of Yb ions in Sc 2O 3 transparent ceramics was about 883 μs. According to the absorption and fluorescence band centers of Yb: Sc 2O 3 transparent ceramics, the level scheme of Yb 3+ ions in Sc 2O 3 ceramics could be gotten.

Investigation on the Spectroscopic Properties of Yb3+-doped Phosphate Glass

A series of the Yb3+ -doped phosphate laser glass have been prepared under high temperature and different doping content and the fluorescence and absorption spectrum is observed, respectively. The influences of the Yb3+ -doped content on the spectral properties of the glass are analyzed and the optimal mole fraction is 4 %. The emission cross-section and fluorescent lifetime is calculated with McCumber theory. Furthermore, the integrated absorption cross-section, the full width at half maximum of the emission spectra and the laser performance parameters such as least particle count, saturation pump intensity and lowest pump intensity of Yb3+ -doped laser glass is calculated.

Crystal Structure and Properties of Yb5Ni4Ge10

AbstractThe new compound Yb5Ni4Ge10 was obtained as single crystals in high yield from reactions run in liquid indium. Single‐crystal X‐ray diffraction data showed that it crystallizes in the Sc5Co4Si10 structure type in the tetragonal space group P4/mbm. The structure is a three‐dimensional framework of [Ni4Ge10] atoms with voids filled by Yb atoms. The Ni and Ge atoms form pentagons, hexagons, and octagons along the ab one‐dimensional plane, which are interconnected along the c axis via Ni–Ge–Ni zigzag chains. Magnetic measurements reveal that Yb5Ni4Ge10 crystals show paramagnetic behavior with a lack of long‐range magnetic ordering down to 2 K. The magnetic susceptibility deviates from the Curie–Weiss law below 100 K, presumably because of crystal field effects from Yb3+ ions. In specific heat measurements, the compound exhibits non‐Fermi‐liquid‐like behavior at low temperatures.

Temperature dependence of photoluminescence and magnetic properties in Yb 3+-doped ZnS nanocrystals

Zinc sulfide semiconductor nanocrystals doped with Yb 3+ ions have been prepared through a chemical precipitation method using PVP (polyvinylpyrrolidone) as a capping agent. The structure of the nanoparticles has been analyzed by X-ray diffraction (XRD). The average size of the nanoparticles is found to be 3.7±0.4 nm. Photoluminescence spectra were recorded for doped ZnS nanoparticles as a function of temperature between 9 and 300 K. The results suggest that two emission bands have been observed at different temperatures. The width of 1.269 eV peak increases as temperature is raised. A shift of lower energy emission band has been observed with the change of temperature. Moreover, the magnetic measurement showed that the sample exhibits paramagnetic behavior.

Yb3+掺杂铋酸盐玻璃的低温发光特性

Yb³⁺掺杂铋酸盐玻璃的低温发光特性

Yb3+:Y3NbO7的制备、结构及发光性能

Yb³⁺:Y₃NbO₇的制备、结构及发光性能

Growth and spectroscopic properties of Yb3+/Er3+:CaMoO4 crystal

This paper reports growth and spectroscopic properties of Yb3+/Er3+:CaMoO4 crystal. Yb3+/Er3+:CaMoO4 crystal with dimensions of 20 × 40 mm has been grown by Czochralski method from a flux of Na2MoO4. The spectroscopic properties were investigated. Yb3+/Er3+:CaMoO4 crystal has a strong and broad absorption band with full width at half maximum of 66 nm, which is suitable for diode laser pumping. Two strong up-conversion emission bands at 510–570 nm and 640–690 nm were observed. Based on the rate equation method, the proportion η of the up-conversion emission intensity of 533, 553 and 671 nm was determined to be 57·83%, which indicates the high effective energy transfer and up-conversion process from Yb3+ to Er3+ ion in Yb3+/Er3+:CaMoO4 crystal.

Luminescent properties of Yb3+-doped hexagonal Ln3BWO9 (Ln = Gd, Y)

We report the synthesis and spectroscopic characterization of polycrystalline Yb3+-doped (1, 2, and 5 at %) Ln3BWO9 (Ln = Gd and Y) borotungstates as candidate gain media for diode-pumped near-IR and visible solid-state lasers. Unpolarized luminescence and absorption spectra for the Yb3+ 2 F 7/2→2 F 5/2 transition are measured at T = 77 and 300 K, the lifetime of the 2 F 5/2 excited state is determined, and the emission cross section of the stimulated Yb3+ 2 F 5/2→2 F 7/2 transition in these compounds is evaluated. Offering a combination of nonlinear optical and lasing properties, the Ln3BWO9 (Ln = Gd, Y) hexagonal borotung-states can be used as bifunctional media for diode-pumped lasers with nonlinear laser frequency self-conversion.

Spectroscopic, Thermal, and Laser Properties of Yb:CaNb$_{2}$O$_{6}$ Crystal

In this paper, we report the room temperature spectroscopic and thermal properties and continuous-wave (CW) laser operation of a new Yb:CaNb2O6 crystal. The peak absorption cross section for the E||a polarization is 0.97 times 10-20 cm2 with a full-width at half-maximum of 28 nm at 975 nm. The stimulated emission cross section is 1.19 times 10-20 cm2 at 1062 nm. The thermal conductivities at room temperature are 5.40, 5.15, and 6.05 Wm-1K-1 along the a, b-, and c-axis, respectively. The fracture strength of Yb:CaNb2O6 single crystal is 315 MPa. The properties of Yb:CaNb2O6 crystal were compared with those of typical Yb-doped materials. A CW output power of 801 mW at 1062 nm was obtained with a slope efficiency of 19% by use of diode pumping.

The effect of Yb3+ concentrations on the properties of Yb,Er:YAl3(BO3)4 crystals

The effect of Yb 3+ concentrations on the properties of Yb 3+ and Er 3+ co-doped YAB crystals has been investigated in this paper. The dependence of the emission intensity on the Yb 3+ concentration has been depicted according to the energy transfer model. The decay curves of 2 F 5/2 level of Yb 3+ ion and 4 I 13/2 level of Er 3+ ion in the different Yb 3+ concentration crystals have been measured. The results show that the lifetime of 2 F 5/2 level of Yb 3+ ion is heavily affected by Yb 3+ concentration, contrary to that of 4 I 13/2 level of Er 3+ in the crystals.

Anisotropy in spectroscopic and laser properties of monoclinic Yb:KLu(WO4)2 crystal

We conducted an investigation into the polarized absorption and emission spectra, the absorption for unpolarized pump light, and the continuous-wave (cw) laser properties of the Yb:KLu(WO4)2 crystal. The low symmetry of the crystal leads to strong anisotropy in the crystal spectroscopy; the strongest absorption and emission occur in the polarization direction parallel to the Nm principal axis. The Ng-cut crystal has highest absorption efficiency for unpolarized pump light and largest potential for generating laser output power. With 11 W of cw output power produced by using a 2 mm thick crystal, the optical-to-optical conversion and slope efficiencies amount to 68% and 80%, respectively, with respect to the absorbed pump power.

Physical and Spectroscopic Properties ofYb3+-Doped Fluorophosphate Laser Glasses

The physical properties including refractive index, Abbe number, nonlinear refractive index, microhardness and thermal expansion coefficient, and spectroscopic properties ofYb3+-doped fluorophosphate laser glasses were investigated. The results show that due to the addition of fluoride, mechanical and thermal properties are promoted, emission cross-sectionσemiis also greatly enhanced. The largest gain coefficientσemi·τm(0.824 pm2·ms) can be obtained with the minimum pump intensityImin(1.112 kw/cm2). This kind ofYb3+-doped fluorophosphate glass is an excellent candidate material forYb3+-doped host for high-power generation.

Thermal properties measurement and laser operation of a new Yb: Gd068Lu032VO4 crystal

A new series mixed vanadate crystals, Yb:Gd(x)Lu(1-x)VO(4) (x=0.2, 0.35, 0.53, 0.68 and 0.84), were grown by the Czochralski method. The thermal conductivities of these crystals were measured from room temperature to 280?C, and the thermal conductivities of Yb:Gd(0.68)Lu(0.32)VO(4) at room temperature are 6.4 and 6.9 W m(-1)K(-1) along a- and c-axis, respectively. The material constants of Yb:Gd(x)Lu(1-x)VO(4) series crystals were estimated. The properties of Yb:Gd(x)Lu(1-x)VO(4) series crystals were compared with those of Yb:LuVO(4) and Yb:GdVO(4) crystals. Laser output power of 1.25 W at 1031 nm was obtained with a slope efficiency of 26% by use of diode pumping for Yb:Gd(0.68)Lu(0.32)VO(4) crystal.

Continuous-wave and Q-switched microchip laser performance of Yb:Y_3Sc_2Al_3O_12 crystals

Optical properties of Yb:Y(3)Sc(2)Al(3)O(12) crystal were investigated and compared with those from Yb:YAG crystals. The broad absorption and emission spectra of Yb:Y(3)Sc(2)Al(3)O(12) show that this crystal is very suitable for laser-diode pumping and ultrafast laser pulse generation. Laser-diode pumped continuous-wave and passively Q-switched Yb:Y(3)Sc(2)Al(3)O(12) lasers with Cr(4+):YAG crystals as saturable absorber have been demonstrated for the first time. Continuous-wave output power of 1.12 W around 1032 nm (multi-longitudinal modes) was measured with an optical-to-optical efficiency of 30%. Laser pulses with pulse energy of over 31 microJ and pulse width of 2.5 ns were measured at repetition rate of over 12.7 kHz; a corresponding peak power of over 12 kW was obtained. The longitudinal mode selection by a thin plate of Cr(4+):YAG as an intracavity etalon was also observed in passively Q-switched Yb:Y(3)Sc(2)Al(2)O(12) microchip lasers.

碱金属氟化物对掺Yb3+氟磷酸盐玻璃析晶稳定性和光谱性质的影响

碱金属氟化物对掺Yb³⁺氟磷酸盐玻璃析晶稳定性和光谱性质的影响

Growth and spectroscopic properties of Yb3+:Y0·8La0·2Ca4O(BO3)3 crystal

A Yb3+:Y0·8La0·2Ca4O(BO3)3 crystal with the dimensions of ø16 × 20 mm has been grown by the Czochralski method. The absorption and emission cross-sections of the Yb3+:Y0·8La0·2Ca4O(BO3)3 crystals are 1·37 × 10−20 cm2 at 977 nm and 0·64 × 10−20 cm2 at 1033 nm respectively, which are larger than that of Yb3+:YCa4O(BO3)4 and Yb3+:GdCa4O(BO3)4 crystals. It shows that the spectroscopic properties of Yb3+:Y0·8La0·2Ca4O(BO3)4 crystal can be improved by substituting the part La3+ ions for the Y3+ ions in YCa4O(BO3)4 to form mixed YxLa1−xCa4O(BO3)3.

Growth and spectral properties of Yb,Tm:YAG crystal

The YAG crystal codoped with Yb3+ and Tm3+ has been grown by Czochralski (Cz) method. The crystal structure of the crystal has been determined by X-ray diffraction analysis. The absorption and emission spectra of Yb,Tm:YAG crystal at room temperature have also been studied. The emission cross-sections have been calculated by Fuechtbauer-Ladenburg formula and reciprocity method. (C) 2007 Elsevier B.V. All rights reserved.

Zintl Phase as Thermoelectric Materials: Synthesis, Structure and Properties of Yb5Al2Sb6

AbstractWe present the synthesis, crystal structure, spectroscopic properties, and electronic structure of a new member of the Zintl family, Yb5Al2Sb6. The compound crystallizes in the Ba5Al2Bi6 structure type. A preliminary assessment of its thermoelectric properties including electrical conductivity, thermopower, and thermal conductivity are reported. Moreover, investigations of solid solutions of this phase, doping effects and chemical modifications will be presented. The room temperature conductivity, thermopower and thermal conductivity of Yb5Al2Sb6/0.5Ge were 1100 S/cm, 20 μV/K, and 3.8 W/m.K, respectively.

Luminescence properties of Yb3+/Na+ codoped CaF2 crystal and laser operation with low threshold

Basing on measuring the luminescence spectra at room temperature pumped by 975nm light, the action mechanism of Na+ in the novel Yb3+,Na+:CaF2 crystal was systemically investigated. The relation between the concentration of doping Na+ and the laser operation threshold was analyzed. The optimum match concentration for Yb3+,Na+:CaF2 with low laser threshold was obtained. In the experiment, the lowest laser operation threshold at only 70mW of absorbing pumped power for 2%Yb3+, 3%Na+:CaF2 crystal is realized, which is in good agreement with the analysis of luminescence properties.