Study of Laser-Induced Plasma Emission Spectra of N 2 , O 2 , and Ambient Air in the Region 350 nm to 950 nm

Laser-induced breakdown spectroscopy (LIBS) is a technique where the output from a pulsed laser is focused onto a sample to create an intense plasma. The emission spectrum from the plasma contains quantitative information on the composition of the sample in the region of the breakdown. Growing applications of this technique include remote or in situ measurements where the atmosphere, primarily nitrogen and oxygen, may present spectral interferences. This study was undertaken to evaluate the spectral characteristics of the interference from the nitrogen and oxygen components in air. Of primary interest in this study is the atomic and molecular origin of the emission features. Comparison of the LIBS spectra with NIST atomic emission data is presented.