Project Name: Research on Post-treatment Process and Mechanism of Optical Thin Film Based on Laser Shock Wave
Wenzhou Public Welfare Science and Technology Project.
At present, large-aperture and high-power laser thin film elements are facing a series of more severe challenges, such as higher damage threshold, higher repetition frequency and higher stability, which not only involve the laser damage resistance and damage growth phenomenon under single-pulse laser irradiation, but also include laser damage caused by the stability of optical properties and surface accuracy of thin films. In this project, a new post-processing technology of optical thin film elements based on laser shock strengthening is proposed for the first time, in order to improve the laser damage resistance and long-term operation stability of thin film elements. By analyzing the influence of laser shock post-treatment under different process parameters on the damage behavior of fundamental frequency high reflection film and anti-reflection film by single pulse laser, the experimental law and failure process of corresponding optical film damage under fundamental frequency irradiation are obtained. In addition, the correction equation of total pressure in laser shock process is established, which provides a theoretical basis for optimizing the selection of technological parameters of laser shock post-treatment, and further clarifies the modification process and mechanism of laser shock post-treatment. Starting with the influence of laser shock post-treatment on the water absorption characteristics of fundamental frequency thin film components under different process parameters, the microstructure changes such as bulk density of thin films after shock were discussed, and the influence process and mechanism of laser shock post-treatment on the water absorption performance and long-term operation stability of thin films were studied in combination with the analysis of hydrolysis adsorption process at variable temperature. The new technology is expected to break through the limitations of the existing methods for improving the laser damage resistance of thin films, and provide a new alternative for promoting the development of thin film components in large-scale high-power laser devices to high energy, high precision and high reliability.
