Spatial characterization of the laser-induced plasma plumes generated by IR CO₂ pulsed laser on carbon targets

Abstract

Spatially resolved optical emission analysis was carried out for the plasma plume, produced by high-power tunable IR CO₂ pulsed laser ablation of graphite, at λ=9.621 μm and with laser fluence of 342 J cm⁻². Wavelength-dispersed spectra of the plume, at medium vacuum conditions (P _air=4 Pa) and concentrated close to the target, reveal C, C⁺, C²⁺, C³⁺, C⁴⁺, N, H, O, and molecular emissions between different electronic states of C₂, CN, OH, CH, and NH. The characteristics of the spectral emission intensities from different species have been investigated as functions of the distance (up to 20 cm) from the sample surface. Vibrational temperatures in the laser-induced plasma have been estimated at various distances from the target surface.