Effect of carbon coating on radiation intensity of laser-induced metal plasmas

The working principle of the laser-induced breakdown spectroscopy (LIBS) was interpreted, and how the surface optical properties of metallic materials affects the laser-induced plasma radiation intensity was analyzed. An LIBS experimental system in the air was set up and the laser plasma emission spectrum intensity of carbon coatings with different thickness measured. The results show that the spectral line intensity of the laser-induced plasma increases by 16% to 22% when a bunch of high-energy laser (5 J) acts on the steel sample with a 8 μm thick carbon coating. It proves to be feasible that the laser-induced plasma radiation intensity can be increased by coating a carbon layer on the surface of the steel sample.