Temporal dependence of the enhancement of material removal in femtosecond-nanosecond dual-pulse laser-induced breakdown spectroscopy.
Despite the large neutral atomic and ionic emission enhancements that have been noted in collinear and orthogonal dual-pulse laser-induced breakdown spectroscopy, the source or sources of these significant signal and signal-to-noise ratio improvements have yet to be explained. In the research reported herein, the combination of a femtosecond preablative air spark and a nanosecond ablative pulse yields eightfold and tenfold material removal improvement for brass and aluminum, respectively, but neutral atomic emission is enhanced by only a factor of 3-4. Additionally, temporal correlation between enhancement of material removal and of atomic emission is quite poor, suggesting that the atomic-emission enhancements noted in the femtosecond-nanosecond pulse configuration result in large part from some source other than simple improvement in material removal.
Scaffidi
Jon
J
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.
Pearman
William
W
Carter
J Chance
JC
Colston
Bill W
BW
Angel
S Michael
SM