Influence of YbF3 deposition rate on surface defect density of infrared laser thin film

The properties and derivation of defects in thin film are introduced in this paper. The influence of the deposition rate of YbF3 on the surface defect density of infrared laser thin film is analyzed. The appropriate deposition rate of YbF3 on the thin film is put forward. The result shows that the nodules and concave holes are the main defects in the infrared laser thin film, and that the defect density decreases with the decrease of deposition rate of YbF3. The defect density is only 0.000 675 when deposition rates are 0.4 nm/s for ZnS and 0.2 nm/s for YbF3, respectively.