We report the use of laser-induced fluorescence (LIF) of laser ablation (LA) plumes for standoff applications. The standoff analysis of Al, as major and minor species in samples, is performed in a nanosecond laser-produced plasma created at a distance of $\sim 10\mathrm{m}$. The LIF of LA plumes is carried out by resonantly exciting an Al transition at 394.4 nm (${}^2{\mathrm{S}}_{1/2}-{}^2{\mathrm{P}}_{1/2}$) using a continuous wave (cw) tunable laser and by collecting the direct-line fluorescence signal at 396.15 nm. The spectral resolution of LIF is obtained by scanning the cw tunable LIF laser across the selected Al transition. Our results highlight that LIF provides enhanced signal intensity, emission persistence, and spectral resolution when compared to thermally excited emission.

中文翻译：

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使用激光诱导的荧光对激光产生的等离子体进行隔离分析

我们报告使用激光烧蚀（LA）烟流的激光诱导荧光（LIF），用于支座应用。对铝（作为样品中的主要和次要物种）的距离分析是在以纳秒距离产生的纳秒激光产生的等离子体中进行的$〜10\mathrm{米}$。LA羽的LIF通过共振激发394.4 nm处的Al跃迁来实现（${}^{\mathrm{2个}}{\mathrm{小号}}_{\mathrm{1个}/\mathrm{2个}}-{}^{\mathrm{2个}}{\mathrm{P}}_{\mathrm{1个}/\mathrm{2个}}$），使用连续波（cw）可调激光器，并收集396.15 nm的直线荧光信号。LIF的光谱分辨率是通过在选定的Al跃迁上扫描连续可调谐LIF激光器获得的。我们的结果表明，与热激发发射相比，LIF增强了信号强度，发射持久性和频谱分辨率。