Abstract Our recent study was focused on the emission from Laser Induced Plasma (LIP) at the delay times of tenths of microseconds after the laser pulse. At these long delays, the spectrum is dominated by the broadband molecular emission and plasma induced luminescence (PIL) produced by a luminescent matrix; only solitary atomic emission lines can be seen. Barium fluoride BaF2 activated by thulium (Tm) is a famous scintillator that presents the promising object for LIP in terms of both the potential for BaF molecular emission and Tm3+ PIL. The detection of molecular and PIL bands presents a new opportunity for analysis of halogens and rare-earth elements, which are the difficult objects for LIBS. In this paper, we show that the UV, Green, Extreme Red, and Infrared molecular bands from BaF and blue luminescence from Tm3+ are present in the LIP emission spectra while the detection of atomic emission from F I and Tm I was impossible with the same experimental setup. Thus, the detection of molecular emission and PIL can be more sensitive than the traditional detection of emission from atoms and ions.

中文翻译：

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BaF2-Tm3+ 的激光诱导击穿光谱 (LIBS)

摘要 我们最近的研究集中在激光脉冲后十分之几微秒的延迟时间激光诱导等离子体 (LIP) 的发射。在这些长延迟下，光谱由发光基质产生的宽带分子发射和等离子体诱导发光 (PIL) 主导；只能看到孤立的原子发射线。由铥 (Tm) 激活的氟化钡 BaF2 是一种著名的闪烁体，在 BaF 分子发射和 Tm3+ PIL 的潜力方面为 LIP 提供了有希望的目标。分子和 PIL 波段的检测为卤素和稀土元素的分析提供了新的机会，这些元素是 LIBS 的难点。在本文中，我们展示了紫外线、绿色、极红、来自 BaF 的红外分子带和来自 Tm3+ 的蓝色发光出现在 LIP 发射光谱中，而使用相同的实验设置不可能检测到来自 FI 和 Tm I 的原子发射。因此，分子发射和 PIL 的检测可以比传统的原子和离子发射检测更灵敏。