The study of femtosecond LIBS in Vortex-Gaussian and double Gaussian configurations

Laser-induced breakdown spectroscopy (LIBS) is a fast and efficient method for sample analysis, whose applications are restricted by the detection limit. Here, femtosecond Vortex laser pulse is introduced to improve the detection limit of LIBS. The emission spectra of Al (I) and Si (I) are measured within Vortex-Gaussian configuration as functions of the inter-pulse delay time between these two pulses. For comparison, the corresponding measurements are also performed within double Gaussian scheme. The variations of the LIBS signals on the inter-pulse delay time of Si and Al exhibit different tendencies. This is because the evolution of plasma and the energy absorption are different when the laser pulse is introduced to interact with them, owing to the different properties of metal and semiconductor materials.