Normalization of absorbed energy and pressure in laser-induced breakdown in mono-atomic and molecular gases according to incident laser energy and initial pressure

Abstract

In laser-induced breakdown experiments, the absorbed energy is one of the first measured parameters. For a given optical configuration and incident energy, the measured absorbed energy depending on pressure always exhibits a similar curve for the tested gases: argon, nitrogen, carbon dioxide and air. This work presents an empirical modelling to predict the pressure dependence of the absorbed energy in mono-atomic and molecular gas efficiently. The first series of experiments, involving Ar, N2 and CO2, presents its efficiency over pressure from 50 to 2400 mbar and incident laser energies from ∼15 to ∼135 mJ. The second series presents the effectiveness of this modelling on air. All experiments are conducted with a Nd:YAG laser at 532 nm and a focal radius of 4.23 μm.