Autofocusing Airy Beams for Micrometer Scale Laser Induced Breakdown Spectroscopy

激光诱导击穿光谱（LIBS）是一种常规用于分析材料元素组成的技术。LIBS使用起来相对简单，可以进行快速、实时的分析。脉冲激光聚焦到材料上的一个高强度点，在那里它产生一个短暂的高温微等离子体或“火花”，产生大量的光发射。这种等离子体的原子线发射有助于识别材料中的元素。减少等离子体体积将提高这些方法的分辨率和功率效率，并为新功能打开大门。然而，在实际设备中，在小区域和小体积内沉积足够的能量来产生等离子体是一项重大的技术挑战，因为激光束需要同时聚焦到尽可能小的光斑上，并与光学系统保持尽可能大的距离。Engage项目的目标是解决这些限制，特别是通过引入用于微化学表征和微加工的下一代激光系统，即自动聚焦Airy光束（AABs）。这样的创新将允许取代目前使用的高斯光束与笨重的基于透镜的聚焦系统相结合。相比之下，AABs不绕射，在空间中遵循弯曲的轨迹，在其路径上的障碍物之外自愈，并在预先设计的距离上突然聚焦，而无需透镜或反射镜系统的帮助。使用AABs进行micro-LIBS分析将在紧密聚焦光束的产生和控制方面取得突破性进展，为实现实用、可靠和价格合理的性能增强的新仪器奠定基础。**这个为期6个月的Engage项目将分为两个主要阶段：1)**时空AABs的工程设计，以实现最佳聚焦条件；2)与AABs一起进行micro-LIBS分析的演示。该项目将使Gastops受益于创新的表征技术。

Laser-induced breakdown spectroscopy (LIBS) is a technique used routinely for the analysis of the elemental**composition of materials. LIBS is relatively simple to use and allows for rapid, real-time analysis. A pulsed**laser is focused down to a high intensity spot on the material where it produces a short-lived high temperature**micro-plasma or 'spark' which produces copious amounts of light emission. The atomic line emissions from**such plasmas facilitates the identification of the elements within the material. Reducing the plasma volume**would both increase resolution and power efficiency of these methods, as well as open the door to novel**functionalities. However, depositing energy sufficient to create a plasma within small areas and volumes in**practical devices presents significant technical challenges, as the laser beam needs to be simultaneously**focused into the smallest possible spot and at the largest possible distance from the optical system. The aim of**this Engage project is to address such limitations, in particular by introducing the next generation of laser**systems for micro-chemical characterization and micro-processing, i.e. Autofocusing Airy Beams (AABs).**Such an innovation will allow to replace currently used Gaussian beams combined with bulky lens-based**focusing systems. In contrast, AABs are non-diffracting, follow curved trajectories in space, self-heal beyond**obstacles placed in their path and focus abruptly at a predesigned distance, without the help of lenses or mirror**systems. The use of AABs for micro-LIBS analysis will enable ground-breaking advances in the generation and**control of tightly focused beams, setting the basis for the realization of practical, reliable and affordable new**instruments with enhanced performances.**This six months Engage project will be divided in two main phases related to 1) the engineering of**spatiotemporal AABs to achieve optimal focusing conditions, and 2) the demonstration of micro-LIBS analysis**together with AABs. This project will benefits Gastops with innovative characterization techniques.