Abstract
It has very important application value to investigate the damage mechanism of CaF2 windows irradiated by ultraviolet excimer laser. As significant optical materials, CaF2 windows have been widely used in the ultraviolet photoelectrical field. Because the ultraviolet excimer laser presents favorable characteristics such as short wavelength and high photon energy, the high power excimer lasers are expected to be widely applied in precision laser machining and military field. In this paper, the experiment on damage in CaF2 windows irradiated by 248nm ultraviolet excimer laser was carried out. The damage characteristics of irradiated spots under different experiment conditions were detected by optical microscope. The laser induced damage thresholds of CaF2 windows were calculated by the zero damage probability through linear fitting. The damage mechanism of CaF2 windows were discussed based on the surface characteristics of damage spots. The experimental results indicated that the damage thresholds of zero probability for the 248nm excimer laser to CaF2 windows were 5.6J/cm2 of the incident surface, and 1.1J/cm2 of the exit surface respectively. When CaF2 windows was irradiated by 248nm excimer laser, its damage first occurred to its exit surface, the damage threshold of exit surface was smaller than that of incident surface. As the laser fluence increased gradually, the damage of exit surface was shown to grow exponential and its degree was significantly higher than that of incident surface. This work is helpful to further improve damage resistance of CaF2 windows in high power laser facility. It can provide the necessary references for selection of ultraviolet optical materials and optimization of application.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.