A narrow linewidth stable high-power continuous-wave 3.5% Tin3＋ doped LiYF4 （Tm：YLF） laser is reported. By using dual F P etalons and three Tm：YLF rods in a cavity, laser output of ~60 W at 1907.7nm is obtained w...A narrow linewidth stable high-power continuous-wave 3.5% Tin3＋ doped LiYF4 （Tm：YLF） laser is reported. By using dual F P etalons and three Tm：YLF rods in a cavity, laser output of ~60 W at 1907.7nm is obtained with a slope efficiency of 34.8%. The M2 factor is found to be ~2.0 under an output power of 30 W. In addition, the relaxation oscillation and efficiency of the Tm：YLF laser are also studied. The relaxation oscillation of the Tm：YLF laser is improved obviously by setting the ratio of pump beam to oscillating laser beam as ~1.5：1 and the efficiency is increased in comparison with the ratio of ~1.3：1.展开更多
To improve the formability of W-rare earth electrode, the influence of high-energy pulse on the plasticity property of W-CeOrods was investigated. The effects of current density(J), pulse width(tw), frequency(f), and ...To improve the formability of W-rare earth electrode, the influence of high-energy pulse on the plasticity property of W-CeOrods was investigated. The effects of current density(J), pulse width(tw), frequency(f), and strain rate on the plasticity of W-CeOrods were discussed in detail. Results of tensile tests show that the W-CeOrods applied with the electrical pulses obtain a maximum percentage total elongation at fracture(9.65 %), increased by118.7 % compared to that without pulses. This is owing to both the heat effect and the interaction of current between dislocations and rare earth additions. Electron back scattered diffraction(EBSD)-generated grain boundary(GB) maps suggest that the length of low-angle grain boundaries composed of high-density dislocations decreases after deformation while applying the pulse current. This demonstrates that the short-duration pulsed current enhances the mobility of dislocations. Scanning electron microscopy(SEM) images of the rods after deformation with the pulse current show that the long fiber-shaped additions become discontinuous,which could reduce the stress concentration and hinder the crack propagation.展开更多
文摘A narrow linewidth stable high-power continuous-wave 3.5% Tin3＋ doped LiYF4 （Tm：YLF） laser is reported. By using dual F P etalons and three Tm：YLF rods in a cavity, laser output of ~60 W at 1907.7nm is obtained with a slope efficiency of 34.8%. The M2 factor is found to be ~2.0 under an output power of 30 W. In addition, the relaxation oscillation and efficiency of the Tm：YLF laser are also studied. The relaxation oscillation of the Tm：YLF laser is improved obviously by setting the ratio of pump beam to oscillating laser beam as ~1.5：1 and the efficiency is increased in comparison with the ratio of ~1.3：1.
基金financially supported by the National Key Technology R&D Program of China (No. 2012BAE06 B02)the Beijing Municipal Science and Technology Project (No. Z141100003814008)
文摘To improve the formability of W-rare earth electrode, the influence of high-energy pulse on the plasticity property of W-CeOrods was investigated. The effects of current density(J), pulse width(tw), frequency(f), and strain rate on the plasticity of W-CeOrods were discussed in detail. Results of tensile tests show that the W-CeOrods applied with the electrical pulses obtain a maximum percentage total elongation at fracture(9.65 %), increased by118.7 % compared to that without pulses. This is owing to both the heat effect and the interaction of current between dislocations and rare earth additions. Electron back scattered diffraction(EBSD)-generated grain boundary(GB) maps suggest that the length of low-angle grain boundaries composed of high-density dislocations decreases after deformation while applying the pulse current. This demonstrates that the short-duration pulsed current enhances the mobility of dislocations. Scanning electron microscopy(SEM) images of the rods after deformation with the pulse current show that the long fiber-shaped additions become discontinuous,which could reduce the stress concentration and hinder the crack propagation.
