Development of Resonant Cavity Film for 575 nm All-Solid-State Laser System

Yellow lasers have attracted much attention due to their applications in biomedicine, astronomy and spectroscopy, and the resonant cavity is an important part of lasers. In this work, the resonant cavity film was studied and prepared using physical vapor deposition (PVD) technology to couple and match the optical properties of Dy,Tb:LuLiF4 crystal to generate yellow laser. In the process of film deposition, the substrate temperature has an important influence on the quality of the film. Therefore, we first investigated the effect of HfO2 film quality at different substrate temperatures. Furthermore, the multilayer film was designed to couple and match the optical properties of Dy,Tb:LuLiF4 crystal. According to the designed film system scheme, HfO2 and UV-SiO2 were used as high- and low-refractive index film materials for resonant cavity film preparation using the PVD technique, and the effect of process parameters on the film quality was investigated. A 450 nm pump laser was used to directly pump Dy3+ to excite and generate the yellow laser. In this process, the excited radiation jump occurs in the crystal, and the generated laser in the new band reaches a certain threshold after oscillation and gain in the resonant cavity, thus successfully outputting a 575 nm yellow laser.