Numerical and Experimental Investigations of the Photothermal Effect in Thin Films of Molybdenum Oxide under Laser Ablation

Abstract—The photothermal effect in a molybdenum oxide film with a thickness of 45 nm subjected to laser ablation has been studied. A hypothesis is presented about a link between the heat conductivity coefficient of the dielectric film with the extreme value of the photothermal effect. It has been shown that at a heat conductivity coefficient larger than 5 W/(m K), the rate of temperature variation at the beginning of film heating process sharply decreases, which, together with the peculiarity of temperature distribution, can cause a multidirectional impact on the width of the formed track. It is established experimentally that under continuous laser radiation, in the molybdenum oxide film with a thickness of 45 nm, formation of tracks with a width of nearly 1/2 of the effective diameter of the laser beam is possible.