Picosecond laser-induced damage of HfO 2 -Al 2 O 3 mixture-based mirror coatings in atmosphere and vacuum environments

• Published in: Optical materials express 2023-03, Vol.13 (3), p.667
• Main Authors: Shi, Jun, Zhu, Meiping, Du, Wenyun, Liu, Tianbao, Zhou, Li, Jiang, Youen, Sun, Jian, Li, Jingping, Shao, Jianda
• Format: Article
• Language: English
• ISSN: 2159-3930; 2159-3930
• DOI: 10.1364/OME.483052

The performance of a mixture-based picosecond laser mirror (MPLM) coating, particularly the picosecond (ps) laser-induced damage threshold (LIDT), is investigated. Two types of 1053 nm ps laser mirror coatings are deposited using electron-beam evaporation: an MPLM coating consists of alternating layers of the HfO 2 -Al 2 O 3 mixture and SiO 2 , and a traditional picosecond laser mirror (TPLM) coating consists of alternating layers of HfO 2 and SiO 2 . Comparative studies on the optical, microstructural and mechanical properties, and LIDT are carried out. For an s-polarized 8 ps laser pulse at a wavelength of 1053 nm, the ps-LIDT of the MPLM coating is approximately 1.2 times higher than that of the TPLM coating in both atmosphere and vacuum test environments. Typical damage morphologies and laser-induced temperature simulations by finite element modeling suggest that the enhanced LIDT of the MPLM coating may be attributed to the lower laser-induced temperature rise in the MPLM coating.