K9玻璃表面颗粒污染物的激光清洗

Laser Cleaning of Particulate Contaminants on K9 Glass Surface

采用光学显微镜、紫外-可见-近红外分光光度计、图像分析软件等,对K9玻璃表面的灰尘颗粒污染物进行了激光直接辐照清洗及激光诱导等离子体冲击波清洗研究。结果表明,经激光直接辐照清洗后,其透射率得到大幅度的提高,但对微小颗粒移除效果不佳,且易于引起元件的激光辐照损伤;激光诱导等离子体冲击波清洗,能取得更好的清洗效果,且没有出现基底损伤。经激光诱导等离子体清洗后(激光诱导等离子体距样品表面距离1 mm,等效激光作用脉冲数10个,激光波长1 064 nm,激光能量70.7 m J),K9玻璃表面的355 nm激光损伤阈值(50%损伤几率)由5.8 J/cm^2提高到8.0 J/cm^2,与基底阈值8.5 J/cm^2相当。

Laser cleaning is an environmentally friendly,stable and reliable cleaning method and has no mechanical contact. Laser cleaning also has high efficiency,low cost and other unique advantages,so can be used widely in many engineering applications of accurate positioning and online cleaning. The laser direct cleaning and laser-induced plasma shockwave（ LIPS） cleaning were utilized to remove the dust particles on the surface of K9 glass. The laser cleaning effect was studied by using optical microscopy,spectrophotometer,and image analysis. The results showed that the particles on K9 glass surface were cleaned effectively,except some of the tiny particles. Under high laser fluency irradiation,laser-induced damage was found on the K9 glass surface. The LIPS cleaning achieved better cleaning effect and has no substrate damage. When the distance between the laser-induced plasma and the sample surface was about 1mm,the contaminated K9 glass surface was cleaned by the LIPS cleaning with 10 pulses irradiation at laser wavelength of 1 064 nm,and laser energy of 70. 7 mJ. After the LIPS cleaning,the 355 nm laser-induced damage threshold of the K9 glass surface was improved from 5. 8 J/cm^2 to 8. 0 J/cm^2,and was similar to that of the substrate threshold（ 8. 5J/cm^2 @ 50% damage probability）. This study is helpful to make clear the laser cleaning mechanism and to develop the laser cleaning application,as well as to increase the innovation and exploration in the experimental teaching.