An equivalent method to analyze the electrical effect induced by laser plasma

Electrical effect induced by laser plasma in air is measured using a tiny probe placed in close to a metal target. Analysis shows that the resulting signal wave varies with detection distance. Based on the testing system, an equivalent circuit model was proposed to analyze the formation mechanism and evolution of the electrical signal and its dependence on the probe distance. The observed signal peak polarity overturn was also analyzed and explained. Finally, our method provides an explanation for the effects of the testing angle on the probe signals according to the time and space evolution of the laser plasma.