Laser-induced damage threshold measurements of high reflecting dielectric layers

Abstract

A quest for higher laser powers is one of the main driving forces in development of laser technology. Unfortunately all laser components have some limit to the intensity of optical radiation that can be applied on them - the so-called laser-induced damage threshold (LIDT). To enable further power scaling of laser devices, novel highly resistant optical components have to be developed. Such components are laser crystals, mirrors, fibers and other components typically coated with periodic dielectric layers made using e-beam, sputtering or sol-gel technologies. The production materials and methods of all the mentioned optics are under constant development, which requires a reliable quality test to provide the feedback to the manufacturing process; one of such tests are the measurements of LIDT. LIDT measurement procedure using repetitive laser pulses, as described in ISO 11254-2 standard, is time- and human resource consuming, if performed without automation. We developed an automated station for the measurements of LIDT that greatly reduces the required human resources and allows fast data collection. In this presentation, we briefly describe the main components of this automated LIDT test station. Furthermore we present the comparison of the latest results obtained on LIDT measurements of ZrO2/SiO2, Nb2O5/SiO2, Ta2O5/SiO2 and TiO2/SiO2 periodic high reflecting dielectric layers performed using repetitive nanosecond laser pulses.