Reduction of self-absorption in femtosecond laser-induced breakdown spectroscopy using spark discharge

The self-absorption effect of femtosecond laser-induced breakdown spectroscopy (LIBS) of aluminum with and without spark discharge is investigated in air. The measured time-resolved spectra show strong self-absorption/self-reversal in the absence of spark discharge. Still, when spark discharge is used to enhance the spectral intensity of LIBS, almost no self-reversal effect can be observed from time-resolved spectra. The results show that spark discharge can effectively reduce the self-absorption effect and improve spectral intensity in femtosecond-LIBS.