Thermocavitation and its application for fabrication of micron-sized holes on metallic and dielectric thin films

Abstract

Thermocavitation is a mechanism induced by a focused CW laser beam into a high absorbing solution. As a result an overheated region is created followed by explosive phase transition and consequently the formation of an expanding bubble. Once the bubble reaches a cooler region it collapses very rapidly crating a shock wave. Thermocavitation can be a useful tool for the generation of ultrasonic waves and controlled ablation with the important difference compared with pulsed lasers that low power lasers are required. In particular, the above mentioned pressure waves may be capable of producing damage to substrates, for example, in metallic and dielectric thin films. In this work, we present an application of the thermocavitation phenomena which consist in the formation of micro-holes on thin films of titanium and Indium Tin Oxide (ITO) deposited on glass substrate. The micro holes can be employed as a micrometer light sources or spatial filters.