Spectroscopic Imaging of Laser-Induced Plasma

Abstract

Spectroscopic imaging provides 2D images with full spectral resolution at each pixel. Thus, chemical imaging of an object, as well as other useful information, can be obtained. An imaging spectroscopy method in the visible range is presented and applied to laser plasma. This is a powerful research tool with numerous possible applications. This study is focused on spectroscopic imaging of laser-produced plasmas, and such spectral images (full spectrum at each pixel) are presented for the first time. Detailed information on optical and geometrical effects are obtained, and an insight to the optimization of the laser plasma spectroscopy method is achieved. The size and the spatial shape of the plasma, which can be used for matrix effect compensation, are measured. Similarity maps and classification maps of laser-induced plasma are obtained for the first time. These maps are used for allocation of chemical components in the plasma. The signal to noise ratio maps of the spectra obtained from laser-induced plasmas are provided. These surfaces possess a clear maximum, indicating that there is a preferred site in the plasma, where the emitted light provides the best signal to noise ratio. The performance of the current method is limited by the lack of temporal resolution, although it can be extended by a proper temporal gating.