针对复杂形貌样品微区化学成分难以表征的难题,研制了一套激光共焦诱导击穿光谱(LIBS)显微成像系统。该系统利用反射的连续激光构建高空间分辨的激光共焦显微系统,实现样品的精准定焦及三维形貌测量;利用共光路脉冲激光诱导激发等离子体光谱信号,实现样品微区全元素探测,进而实现具有高空间分辨、抗漂移特性的三维LIBS显微元素成像。实验表明,该系统可以实现横向分辨率为10 μm的多元素图谱成像,系统光谱探测的合成不确定度为2.24%。该系统结合形貌信息和LIBS光谱信息实现三维图谱成像,为生物组织、微纳材料等复杂形貌样品的化学表征提供了新的有效途径。

Considering the urgent demand for the characterization of chemical composition in the micro-zone of samples with complex morphology, we developed a confocal laser-induced breakdown spectroscopy (LIBS) microscope in this study. First, the microscope used the continuous laser reflected from a sample to construct a laser confocal system with high spatial resolution, ensuring accurate focusing and three-dimensional (3D) morphological measurement of the sample. Then, the LIBS signals were excited by common-path pulsed laser to achieve full-elemental detection of the sample, thereby realizing 3D elemental imaging with high spatial resolution and anti-drift properties. The experimental results show that the lateral resolution of multi-elemental maps can reach 10 μm, and the combined uncertainty of the system's spectral detection is 2.24%. Furthermore, 3D elemental maps were constructed after combining with the in-situ morphological information and LIBS information in the system. In conclusion, the system provides new perspectives for the chemical analysis of samples with complex morphology such as biological tissue and micro-nano materials.