This paper used femtosecond Gaussian and vortex beams to ablate a Cu target and generate Cu plasmas. A Gaussian beam pulse is shaped into a vortex beam by a vortex wave plate (topological charge m = 1). The spectral intensity of Cu plasmas produced by the two lasers was measured, finding that the spectra with vortex beam were stronger than that with Gaussian beam. The spectral intensity was doubled by simply changing the Gaussian beam into the vortex beam. In addition, the position for maximum Cu atomic line emission along with the laser path was closer to the position of focusing-lens with increasing laser energy. Finally, the Boltzmann plot calculated the plasma temperature, finding that the plasma temperature with the vortex beam was also higher than that with the Gaussian beam. The results indicated that vortex beams could improve the spectral intensity of the femtosecond laser-induced plasmas.

中文翻译：

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使用涡旋光束增强飞秒激光诱导击穿光谱的发射

本文使用飞秒高斯和涡旋光束烧蚀 Cu 靶并产生 Cu 等离子体。高斯光束脉冲被涡旋波片（拓扑电荷）整形为涡旋光束米= 1). 测量了两种激光器产生的Cu等离子体的光谱强度，发现涡旋光束的光谱比高斯光束的光谱强。通过简单地将高斯光束变为涡旋光束，光谱强度加倍。此外，随着激光能量的增加，最大Cu原子线发射的位置沿着激光路径更接近聚焦透镜的位置。最后，玻尔兹曼图计算了等离子体温度，发现涡旋光束的等离子体温度也高于高斯光束。结果表明，涡旋光束可以提高飞秒激光诱导等离子体的光谱强度。