Experimental Investigation of the Nonlinear Photothermal Effect in the Process of Laser Ablation of Oxide Films with Different Thermal Conductivity Coefficients

The nonlinear photothermal effect that occurs during laser ablation of metal oxide films with different thermal conductivities is investigated. It is shown that the track width decreases monotonously with a change in the thermal conductivity coefficient in the range from 25 to 1 W/(m K). It was found that a moderate decrease in the thermal conductivity of the film does not lead to a significant decrease in the track width. The conclusion is made about the combined effect of the thermal conductivity coefficient and thermal acceleration factor on the minimum track width, which introduces an additional nonlinearity into the heating process of the oxide film.