Preparation And Characterization Of Laser Induced Damage Of Thin Films

In this paper, we try to make the appropriate proportion of Ti O₂ solution and Ta₂O₅ solution, and finally we get the preparation solution of a good stable performance and good effect of films. During the preparation of thin film samples, the preparation of the solution, the process of film coating, and heat treatment process of films all have a great influence on the optical properties of the films and the laser induced damage threshold of the films. We have carried on the exploration research in order to find the suitable conditions to solve the problems.In the process of the research, we have adopted a variety of methods to test the properties of the film samples, and evaluate the properties of the film samples.Through exploration and characterization experiments, we draw the following conclusions: the solution needs certain aging time, the solution of Ti O2 is aged about 7 days, and the solution of Ta2O5 is aged about 20 days. In the process of film coating, we need to effectively control the temperature and humidity of environment, the temperature is about 20℃,and the humidity must be less than 35%, both temperature and humidity have the especially obvious effects on the process of the Ta2O5 film coating. Meanwhile, the spin coating is prone to appear radial streaks of films, but the dip coating can effectively reduce or avoid appearing radial streaks of films.In the subsequent heat treatment process of film samples, we found that the slow heating films can effectively prevent cracking, and the rate of heating has an especially obvious effect on the Ti O2 films. The atmosphere of pure oxygen under certain pressure and the longer period of time can reduce or prevent discoloration of the films during the process. When we adopt a higher heat treatment temperature,it can improve the refractive index of the film samples. while higher heat treatment temperature and longer heat treatment time may be good to the volatile organic compounds and carbon disappear thoroughly in the films,thereby reducing the degree of discoloration of the films. But we also found both titanium films and Ta2O5 films have the higher laser threshold, when using low temperature heat treatment. Thus, in the experiment, we need comprehensive consideration of all factors.