Research progress on ultraviolet enhanced gold mirrors suitable for submirrors of large telescopes

Due to the large number of sub-mirrors for very large telescope, the recoating is heavy workload, so the reflector needs to take into account the film efficiency and life. Based on the requirements of China's great telescope, we carried out the experimental research on UV-enhanced silver reflective film system. The contents include the design of UV-enhanced silver reflective film system, the UV- enhanced silver reflective film system plating process, and the film life and environmental stability verification tests. The experimental results show that the method is successful in broadening the silver film to the ultraviolet band. It can greatly improve the lifetime and environmental stability of the film, and is suitable for application to extremely large splicing astronomical telescope.