New progress in research on laser cleaning and improving the damage threshold of fused quartz components at Shanghai Optics and Machinery Institute

Recently, the research team of the High Power Laser Element Technology and Engineering Department of the Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences, has made new progress in the study of improving the damage threshold of fused quartz elements through laser cleaning. The study proposes for the first time the use of microsecond pulse CO2 laser cleaning to enhance the damage resistance performance of fused quartz components. The relevant research results were published in the International Journal of Mechanical Sciences under the title "Microsecond pulsed CO2 laser cleaning of high damage threshold fused silica".

With the development of modern optical technology, the problem of ultraviolet laser-induced damage to fused quartz components seriously restricts the development of high-power laser systems. At present, the contact polishing process inevitably produces defects and pollution, and it is difficult to completely remove them through post-treatment, greatly reducing the performance and lifespan of fused quartz components.

Principle and experimental schematic diagram of microsecond pulse CO2 laser cleaning
To this end, the research team revealed the modulation mechanism of defects and pollution on component damage performance through a multi-scale simulation method of macro micro nano scale. Through multimodal characterization of the distribution patterns of defects and contamination, it has been confirmed that laser cleaning can effectively eliminate and suppress surface/subsurface defects, absorption defects, chemical structural defects, and elemental contamination, without generating residual thermal stress and severely damaging the surface roughness of materials. The samples cleaned by laser showed a higher damage threshold compared to those processed by traditional processing techniques (mechanical chemical polishing, mechanical chemical polishing+magnetorheological polishing, mechanical chemical polishing+hydrofluoric acid etching). The damage threshold increased by 47.6% with a 0% probability and 27.0% with a 100% probability, respectively. The laser cleaning method proposed in this study provides a new approach for the low defect and clean manufacturing of fused quartz components.

The related work has received support from key research and development programs of the Ministry of Science and Technology, the National Natural Science Foundation of China, and the Shanghai Sailing Plan.

Source: Shanghai Institute of Optics and Mechanics