Vassilia Zorba

Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

Ultrafast Laser Ablation Sampling Technologies in Optical Emission Elemental and Isotopic Imaging

Abstract

 

Laser ablation-based optical emission spectroscopy enables in situ, near real time, spatially- and axially- resolved chemical analysis and imaging without sample preparation. The advent of ultrafast lasers and their use in plasma spectroscopy over the past few years has enabled high-resolution elemental analysis capabilities and suppressed matrix effects, which have resulted in improved analytical performance. In this talk we discuss the use of emerging femtosecond laser technologies in optical emission spectroscopy, such as femtosecond optical vortex beams, laser filamentation, ultrafast sampling in optical near-field, and sub-micron ablation for elemental and isotopic analysis with Laser Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Molecular Isotopic Spectrometry (LAMIS).

 

Specifically, we introduce ultrafast optical vortex beams with varying orbital angular momentum as sampling tools in optical emission spectroscopy, and present the influence of topological charge on the laser-induced plasma properties and LIBS emission. We also demonstrate the ability to perform standoff isotopic analysis at extended distances (85 m) through the combination of femtosecond filaments and LAMIS (F2-LAMIS). Near-field femtosecond laser sampling is studied as a way to beat the diffraction limit in laser ablation sampling, and tightly focused femtosecond beams are used in the far-field to improve spatial resolution and absolute limits of detection in LIBS down to the attogram scale. Finally, we demonstrate the use of femtosecond laser pulses and resulting separations in the laser induced plasma for high-resolution 3D elemental imaging in a variety of applications, with special emphasis on Li-ion batteries.

 



Date: 15/9/2017
Time:11:00 (coffee & cookies will be served at 10:45)
Place:FORTH Seminar Room 1