Gibbs David Ken, Podsednik Maximilian, Tapler Patrick, Weiss Maximilian, Opitz Alexander Karl, Nelhiebel Michael, Quarles Charles Derrick, Larisegger Silvia, Limbeck Andreas
TU Wien, Institute of Chemical Technologies and Analytics, Getreidemarkt 9/164, 1060 Vienna, Austria.
KAI Kompetenzzentrum Automobil- und Industrieelektronik GmbH, Argentinierstrasse 8, 1040 Vienna, Austria.
Chem Biomed Imaging. 2024 Jul 25;2(9):631-639. doi: 10.1021/cbmi.4c00045. eCollection 2024 Sep 23.
Elemental imaging in laser-induced breakdown spectroscopy is usually performed by placing laser shots adjacent to each other on the sample surface without spatial overlap. Seeing that signal intensity is directly related to the amount of ablated material, this restricts either spatial resolution (for a given excitation efficiency) or sensitivity (when reducing the laser spot size). The experimental applicability of a concept involving the spatial overlapping of shots on the sample surface is investigated and compared to the conventional approach. By systematic choice of spacing between laser shots, spatial resolution can be improved to the single digit micrometer range for a given laser spot size. Signal intensity is found to be linearly dependent on the area ablated per shot, facilitating larger signal-to-background ratios with increased spot sizes. Owing to this, the presented approach is also employed to enhance signal intensity, while preserving spatial resolution. The applicability of the method is explored by analyzing samples with distinct thickness of the surface layer, allowing for the assessment of the concept's suitability for different sample types.
激光诱导击穿光谱中的元素成像通常是通过在样品表面将激光脉冲彼此相邻放置而不产生空间重叠来进行的。鉴于信号强度与烧蚀材料的量直接相关，这限制了空间分辨率（对于给定的激发效率）或灵敏度（当减小激光光斑大小时）。研究了一种涉及样品表面脉冲空间重叠概念的实验适用性，并与传统方法进行了比较。通过系统地选择激光脉冲之间的间距，对于给定的激光光斑大小，空间分辨率可以提高到个位数微米范围。发现信号强度与每次脉冲烧蚀的面积呈线性相关，随着光斑尺寸的增加，有利于获得更大的信噪比。因此，所提出的方法也被用于增强信号强度，同时保持空间分辨率。通过分析具有不同表面层厚度的样品来探索该方法的适用性，从而评估该概念对不同样品类型的适用性。
