中国物理B ›› 2020, Vol. 29 ›› Issue (5): 54209-054209.doi: 10.1088/1674-1056/ab8206

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Optical modulation of repaired damage site on fused silica produced by CO2 laser rapid ablation mitigation

Chao Tan(谭超), Lin-Jie Zhao(赵林杰), Ming-Jun Chen(陈明君), Jian Cheng(程健), Zhao-Yang Yin(尹朝阳), Qi Liu(刘启), Hao Yang(杨浩), Wei Liao(廖威)   

  1. 1 State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China;
    2 Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
  • 收稿日期:2020-01-09 修回日期:2020-02-22 出版日期:2020-05-05 发布日期:2020-05-05
  • 通讯作者: Ming-Jun Chen, Jian Cheng E-mail:chenmj@hit.edu.cn;cheng.826@hit.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51775147 and 51705105), the Science Challenge Project of China (Grant No. TZ2016006-0503-01), the Young Elite Scientists Sponsorship Program by CAST (Grant No. 2018QNRC001), the China Postdoctoral Science Foundation funded project (Grant Nos. 2018T110288 and 2017M621260), the Self-Planned Task of State Key Laboratory of Robotics and System (HIT) (Grant Nos. SKLRS201718A and SKLRS201803B).

Optical modulation of repaired damage site on fused silica produced by CO2 laser rapid ablation mitigation

Chao Tan(谭超)1, Lin-Jie Zhao(赵林杰)1, Ming-Jun Chen(陈明君)1, Jian Cheng(程健)1, Zhao-Yang Yin(尹朝阳)1, Qi Liu(刘启)1, Hao Yang(杨浩)1, Wei Liao(廖威)2   

  1. 1 State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China;
    2 Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
  • Received:2020-01-09 Revised:2020-02-22 Online:2020-05-05 Published:2020-05-05
  • Contact: Ming-Jun Chen, Jian Cheng E-mail:chenmj@hit.edu.cn;cheng.826@hit.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51775147 and 51705105), the Science Challenge Project of China (Grant No. TZ2016006-0503-01), the Young Elite Scientists Sponsorship Program by CAST (Grant No. 2018QNRC001), the China Postdoctoral Science Foundation funded project (Grant Nos. 2018T110288 and 2017M621260), the Self-Planned Task of State Key Laboratory of Robotics and System (HIT) (Grant Nos. SKLRS201718A and SKLRS201803B).

摘要: CO2 laser rapid ablation mitigation (RAM) of fused silica has been used in high-power laser systems owing to its advantages of high efficiency, and ease of implementing batch and automated repairing. In order to study the effect of repaired morphology of RAM on laser modulation and to improve laser damage threshold of optics, an finite element method (FEM) mathematical model of 351 nm laser irradiating fused silica optics is developed based on Maxwell electromagnetic field equations, to explore the 3D near-field light intensity distribution inside optics with repaired site on its surface. The influences of the cone angle and the size of the repaired site on incident laser modulation are studied as well. The results have shown that for the repaired site with a cone angle of 73.3°, the light intensity distribution has obvious three-dimensional characteristics. The relative light intensity on z-section has a circularly distribution, and the radius of the annular intensification zone increases with the decrease of z. While the distribution of maximum relative light intensity on y-section is parabolical with the increase of y. As the cone angle of the repaired site decreases, the effect of the repaired surface on light modulation becomes stronger, leading to a weak resistance to laser damage. Moreover, the large size repaired site would also reduce the laser damage threshold. Therefore, a repaired site with a larger cone angle and smaller size is preferred in practical CO2 laser repairing of surface damage. This work will provide theoretical guidance for the design of repaired surface topography, as well as the improvement of RAM process.

关键词: fused silica, laser repaired surface, optical modulation, finite element method (FEM)

Abstract: CO2 laser rapid ablation mitigation (RAM) of fused silica has been used in high-power laser systems owing to its advantages of high efficiency, and ease of implementing batch and automated repairing. In order to study the effect of repaired morphology of RAM on laser modulation and to improve laser damage threshold of optics, an finite element method (FEM) mathematical model of 351 nm laser irradiating fused silica optics is developed based on Maxwell electromagnetic field equations, to explore the 3D near-field light intensity distribution inside optics with repaired site on its surface. The influences of the cone angle and the size of the repaired site on incident laser modulation are studied as well. The results have shown that for the repaired site with a cone angle of 73.3°, the light intensity distribution has obvious three-dimensional characteristics. The relative light intensity on z-section has a circularly distribution, and the radius of the annular intensification zone increases with the decrease of z. While the distribution of maximum relative light intensity on y-section is parabolical with the increase of y. As the cone angle of the repaired site decreases, the effect of the repaired surface on light modulation becomes stronger, leading to a weak resistance to laser damage. Moreover, the large size repaired site would also reduce the laser damage threshold. Therefore, a repaired site with a larger cone angle and smaller size is preferred in practical CO2 laser repairing of surface damage. This work will provide theoretical guidance for the design of repaired surface topography, as well as the improvement of RAM process.

Key words: fused silica, laser repaired surface, optical modulation, finite element method (FEM)

中图分类号:  (Beam characteristics: profile, intensity, and power; spatial pattern formation)

  • 42.60.Jf
42.70.Ce (Glasses, quartz) 46.15.-x (Computational methods in continuum mechanics)