Near fundamental nanosecond laser damage resistance of nanostructured all-silica mirrors at 355 nm by local laser irradiation

Abstract

Laser damage resistance of coatings is determined by thin film materials and multilayer designs, all of which limit the overall performance of optical elements and all laser systems. Coatings that consist of high band-gap materials and are capable to withstand extreme laser power under the multiple pulse irradiation, could substantially expand the current capabilities of generated laser power in major laser facilities. In this report all-silica high reflectivity mirrors were coated using GLAD method and have been locally irradiated by the pulsed laser in order to gain close to fundamental laser damage resistivity. Optical elements exceeded the optical resistivity of fused silica substrate and reached 200 J/cm2 in pulsed ns regime at 355 nm wavelength. The achieved major laser damage resistivity improvement of high reflectivity mirrors will have an essential effect in major laser facilities working towards laser fusion.