Deguchi, Y. ; Chong, D. T. ; Ikutomo, A. ; Liu, J. P. ; Liu, R. W. ; Shiou, F. J. ; Yan, J. J. ; Zhang, Z. Z.
Long pulse; dual-pulse laser-induced breakdown spectroscopy; DP-LIBS; enhancement; plasma temperature stabilization; underwater measurement;CO2-LASER PULSE; AMBIENT GAS; ABLATION; ENHANCEMENT; PRESSURES; FEASIBILITY; MAGNESIUM; DISCHARGE; SPECTRUM; LIQUIDS
Collinear long and short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) was employed to clarify the emission characteristics from laser-inducedplasma. The plasma was sustained and became stable by the long pulse-width laser with the pulse width of 60s under free running (FR) conditions as an external energy source. Comparing the measurement results of stainless steel in air using single-pulse LIBS (SP-LIBS) and DP-LIBS, the emission intensity was markedly enhanced using DP-LIBS. The temperature of plasma induced by DP-LIBS was maintained at a higher temperature under different gate delay time and short pulse-width laser power conditions compared with those measured using short SP-LIBS. Moreover, the variation rates of plasma temperatures measured using DP-LIBS were also lower. The superior detection ability was verified by the measurement of aluminum sample in water. The spectra were clearly detected using DP-LIBS, whereas it cannot be identified using SP-LIBS of short and long pulse widths. The effects of gate delay time and short pulse-width laser power were also discussed. These results demonstrate the feasibility and enhanced detection ability of the proposed collinear long and short DP-LIBS method.