Effects of aerosols and laser cavity seeding on spectral and temporal stability of laser-induced plasmas: Applications to LIBS

The spectral and temporal effects of laser cavity seeding and aerosol presence in the laser-induced plasma volume are investigated with the goal of examining factors affecting the precision of laser-induced breakdown spectroscopy. Improvements in the temporal stability of laser-induced breakdown initiation were observed with laser cavity seeding. However, laser cavity seeding produced no significant improvement in analyte precision for a range of gas-phase atomic emission lines, including nitrogen, hydrogen, and carbon. In contrast, greater shot-to-shot analyte precision, as measured by a nearly 60% reduction in relative standard deviation, was realized with the elimination of concomitant aerosols from the analyte sample stream. Such findings are consistent with the expected interactions of ambient aerosols and the laser-induced breakdown process.