A laser may not be the first tool most geoscientists think to use when analyzing geological samples, but the technique known as laser-induced breakdown spectroscopy (LIBS) holds great potential for illuminating the geosciences.
It’s a very simple technique: by rapidly pulsing a high-powered laser at any given sample, a plasma is formed on its surface and the sample’s atoms within are excited. As the atoms decay back to their ground state, they emit light at specific wavelengths, which can be spectrally analyzed to obtain a kind of geochemical fingerprint of the sample’s atomic elements.
Because LIBS can capture the entire elemental composition of a sample, it is a versatile technique that can be readily applied in many different scientific domains. Over his career, Harmon has used LIBS in a variety of ways, including evaluating environmental lead contamination, sussing out obsidian sources, and analyzing carbonates and silicates.
The speed and versatility of LIBS make it a “geochemical tool for the 21st century,” according to Russell Harmon (NC State University) and Giorgio S. Senesi, a researcher at the Italian National Research Council (Cnr). It is capable of quantitative and qualitative analysis of the elemental composition of materials such as rocks, minerals, metals, sediments, soils, archaeological artifacts, gases, liquids, explosives, and beyond. It’s also useful both in the laboratory and in the field, on Earth or off it.
Giorgio Saverio Senesi
CNR – Istituto per la scienza e tecnologia dei plasmi