Optical emission enhancement using laser ablation combined with fast pulse discharge

In this paper, a high voltage and fast pulse discharge circuit is developed and combined with laser ablation to enhance optical emission from Si crystal. The new characters of the discharge circuit and its effect on the plasma emission are presented. Characterizing by a damping and periodical oscillating discharge voltage and current with a short period of similar to 0.5 mu s, the discharge automatically occurs similar to 1 mu s after laser ablation. Significant optical emission enhancement, up to 52 times improved signal intensity relative to the signal in the absence of the discharge spark, is observed. Better line stability in terms of relative standard deviation and improved signal to noise (S/N) ratio are also achieved. The enhanced line intensity with better stability and S/N ratio, similar with the observation when using double-pulse laser induced breakdown spectroscopy (DP-LIBS), probably will benefit element analysis in the future. (C) 2010 Optical Society of America