TESTING AND VERIFICATION METHODS FOR DIELECTRIC MIRRORS USED IN FEMTOSECOND REGIME LASER SYSTEMS

This paper presents the methodology and reports the results concerning the Laser Induced Damage Threshold (LIDT), surface quality and group delay dispersion (GDD) measurements of large aperture femtosecond laser mirrors, achieved in a project funded by IFA under the contract number 02 ELI/18.10.20.17., having, as a main goal, the manufacturing of large aperture mirrors (150mm effective diameter) and tests performing for use in high energy ultra-short pulse laser systems, such as ELI-NP and CETAL infrastructures. The manufacturing process of the mirror substrates was described in a previous paper [1] and the coating technology will be presented in a future article. The novelty of this paper consists, mainly, in the method, experimental arrangement and test procedure to determine the Laser Induced Damage Threshold (LIDT) but also in the entire testing protocol, including Group Delay Dispersion (GDD) and other measurements presented here.