Reduction of nanoparticles in optical thin films through ion etching.

Contaminating particles in optical thin films can lead to the formation of nodules and reduction of laser induced damage threshold (LIDT). This work investigates the suitability of ion etching of the substrates to reduce the impact of nanoparticles. Initial investigations suggest that ion etching can remove nanoparticles from the sample surface; however, doing so introduces texturing to the surface of the substrate. This texturing leads to an increase in optical scattering loss, though LIDT measurements show no significant reduction in the durability of the substrate.