Zaremba Gytis, Paipulas Domas, Vaičaitis Virgilijus, Balachninaite Ona
Laser Research Center, Vilnius University, LT, Vilnius, Lithuania.
Appl Spectrosc. 2024 Jun;78(6):579-590. doi: 10.1177/00037028241240782. Epub 2024 Apr 3.
In this work, we present studies on the effect of laser wavelengths on the laser-induced plasma characterization using a femtosecond (fs) ytterbium-doped potassium-gadolinium tungstate (Yb:KGW) laser. Plasma plumes of copper, steel, ceramics, and glass samples were induced using a multiple shot of 200 fs laser pulses with 1030 nm and 343 nm wavelengths at fixed laser fluence () and analyzed using the laser-induced breakdown spectroscopy (LIBS) technique. Time-resolved fs-LIBS measurements were performed on the same set of samples and under the same experimental conditions. For the calculation of plasma parameters, the set of spectral lines of Cu(I) (for copper sample), Fe(I) (for steel sample), and Ca(I), K(I) (for glass and ceramics samples) were observed. The plasma electron temperature and density were evaluated from the Boltzmann plots and Stark-broadening profiles of the plasma spectral lines, assuming the local thermodynamic equilibrium condition. Time-resolved plasma temperature and electron density for fs-LIBS using ultraviolet (UV) and infrared (IR) laser wavelengths were analyzed and no significant dependence on fs laser wavelength was observed for any of the samples. However, for all samples the signal-to-noise ratio (SNR) significantly increased using UV laser radiation: copper (), steel (), glass (), and ceramics (). Therefore, by using a fs UV laser wavelength for laser-induced breakdown spectroscopy experiments, for certain materials the SNR and at the same time the limit of detection can be significantly enhanced.
在这项工作中，我们展示了关于激光波长对使用飞秒（fs）掺镱钨酸钾钆（Yb:KGW）激光器产生的激光诱导等离子体特性影响的研究。在固定激光能量密度（）下，使用波长为1030 nm和343 nm的200 fs激光脉冲多次激发铜、钢、陶瓷和玻璃样品的等离子体羽流，并使用激光诱导击穿光谱（LIBS）技术进行分析。在相同的实验条件下，对同一组样品进行了时间分辨飞秒LIBS测量。为了计算等离子体参数，观察了Cu(I)（对于铜样品）、Fe(I)（对于钢样品）以及Ca(I)、K(I)（对于玻璃和陶瓷样品）的光谱线集。假设处于局部热力学平衡条件，根据等离子体光谱线的玻尔兹曼图和斯塔克展宽轮廓评估等离子体电子温度和密度。分析了使用紫外（UV）和红外（IR）激光波长的飞秒LIBS的时间分辨等离子体温度和电子密度，未观察到任何样品对飞秒激光波长有显著依赖性。然而，对于所有样品，使用紫外激光辐射时信噪比（SNR）显著提高：铜（）、钢（）、玻璃（）和陶瓷（）。因此，通过在激光诱导击穿光谱实验中使用飞秒紫外激光波长，对于某些材料，信噪比以及同时检测限可以显著提高。
