Study On The Theory Of Interaction Between The High-energy Laser And The Optical Thin-film

The optical thin film is the important parts in the laser systems. For the laser systems, optical thin film usually has the lower damage threshold related to the other optical components. It is the important factor that limits the development of lasers. It is of important value to improve the damage threshold of the thin film coatings for the development of laser systems.The main result of the interaction between the high-energy laser and optical thin film is the thermally-induced damage. After the absorption of laser energy, the temperature of thin film rise to the melting point and be melted. The physical model was built. With the help of the computer, the result was given. Under the laser irradiation, the temperature of the thin film starts to rise. In the center of the thin film, the temperature of the thin film rise faster. It is continued to the end of the irradiation process. Then, the temperature of the thin film starts to go down. Similarly, in the center of the thin film, the temperature of the thin film goes down faster. The laser-induced damage starts in the center of the thin film.Damage threshold is an important criterion of the optical thin film. This article discusses the testing method of the damage threshold of the optical thin film. Because of the different structures of the thin film, the different interaction between the laser and the optical thin film, the different testing method of the damage threshold of the optical thin film and the different judgment method of the damage threshold of the optical thin film, the testing results of each laboratory is not comparable.The method to improve the damage threshold of the optical thin film was discussed from two considerations of physics and chemistry. According to the different film materials, using appropriate methods, the damage threshold of the thin film can be improved.