Cleaning of Micrometer SiO₂ Contamination on Glass Insulator Surface by 1 064 nm Laser

As a new efficient and environmentally friendly cleaning method, laser cleaning has a good application prospect in insulator cleaning. The distribution characteristics of temperature field and stress field of laser cleaning glass insulator were studied by using multi-physical simulation software. The influences of the thickness of pollution layer, laser scanning speed and glass absorption coefficient on the laser cleaning effect were analyzed. Finally, the reliability and safety of the laser cleaning were verified by experiments. The results show that the decontamination mechanism of thermal stress has theoretical feasibility. The temperature distribution presents an uneven layered distribution in the longitudinal direction, and the temperature rise and stress increase with the increase of laser power. When the average power of pulsed laser is 200 W and the thickness of silica pollution layer is 50 μm (2 ms), the compressive stress is greater than the pollution adhesion. The temperature and stress of the glass - pollution interface will decrease with the increase of pollution thickness. When laser scanning is used for irradiation, the average power of 200 W pulse laser which is used to scan the thickness at the speed of 1.5 m/s for 50 μm pollution surface can achieve the purpose of decontamination. In the case of laser direct irradiation to clean the glass surface, because the absorption coefficient of the glass to the laser is small, the glass insulator produces a small temperature rise, which will not cause damage to the tempered glass substrate.