摘要
激光清洗具有非接触、精度高等优点,被广泛应用于光学玻璃元件表面的微纳米颗粒污染物的清洗。光学玻璃的材质、激光清洗能量及微纳米颗粒污染物的尺寸等参数对清洗的效果影响显著,尤其是选择恰当的激光能量是决定玻璃表面微纳颗粒清洗效果的关键。研究激光与玻璃表面微纳米颗粒的作用机理,通过分析作用过程的综合效应预测清洗效果,选择合适的清洗能量,达到理想的清洗效果。建立清洗过程的热/热应力模型,利用COMSOL进行仿真,得到当激光能量密度大于0.764 J/cm^(2)时,由于热应力的作用使粒径大于1μm的微纳米污染物剥离玻璃表面,表面得到清洗且无热损伤,当激光能量超过1.426 J/cm^(2)时,由于热效应颗粒温度超过玻璃基底的熔点以产生的热应力与冲击波,导致玻璃表面出现损伤。以K9玻璃为基底材料,氧化铈颗粒作为玻璃表面的污染物,采用颗粒沉积的方法制备清洗样本,并进行激光清洗实验和分析。实验表明,0.815 J/cm^(2)的激光能量使玻璃表面大颗粒得到较好的清洗效果,当清洗能量密度增大到1.120 J/cm^(2)时清洗效果进一步提高,当能量密度为1.426 J/cm^(2)时,玻璃表面出现明显的热力学损伤,如凹坑、形变。实验与理论结果一致。
Objective In the laser system,the micro-nano impurities attached to the optical glass surface will cause additional modulation of the beam,the laser beam quality and the damage threshold of the optical component will be reduced,and even the output and load capacity of the laser device will be affected.Therefore,in order to improve the stability and reliability of the optical system,it is necessary to maintain the cleanliness of the optical components.For the micro and nano pollutants on the surface of optical glass,laser cleaning is used to clean.In particular,the selection of suitable laser energy is the key to determine the cleaning effect of micro and nano particles on the glass surface.In order to achieve the ideal cleaning effect,it is necessary to study the mechanism of the interaction between laser and micro-nano particles on the glass surface.By analyzing the comprehensive effect of the action process to predict the action effect,the appropriate cleaning energy can be selected.Methods The sample was prepared by particle deposition,K9 glass is used as the substrate,cerium oxide particles are used as the pollutants on the glass surface,and the laser cleaning experiment and analysis are carried out.For different laser energy,the micro and nano particles are cleaned in two ways:"forward"and"back".Among them,in the"forward"cleaning,the particle is located above the glass base,the laser is cleaned from top to bottom,and on the contrary,it is"back"cleaning.The cleaning effect for different energy and the thermodynamic damage of glass substrate by different cleaning methods are analyzed by experiment.At the same time,the thermal stress model of the cleaning process was established,and COMSOL was used for simulation to analyze the mechanism of the interaction between the laser and the micro-nano particles on the optical glass surface and the thermodynamic effect of the particles on the substrate.Results and Discussions The experiment shows that the backward cleaning is better than the forward cleaning.By using the method of backward cleaning,for the laser energy of 0.815 J/cm^(2),the large particles on the glass surface can be cleaned better.And for increasing the laser energy to 1.120 J/cm^(2),the cleaning effect is further improved(Fig.9).The laser energy of 1.426 J/cm^(2) causes obvious thermodynamic damage on the surface,such as pits and deformation(Fig.10).The simulation results show that for laser energy greater than 0.764 J/cm^(2),the micro and nano pollutants with particle size greater than 1μm can be stripped off the glass surface due to thermal stress.The glass surface is cleaned without heat damage.However,if the laser energy exceeds 1.426 J/cm^(2),the thermal stress and shock wave generated by the thermal effect and particle temperature exceeding the melting point of the glass substrate will cause damage to the glass surface(Fig.3).Conclusions The cleaning samples were prepared by particle deposition method and the laser cleaning experiments were carried out.The results indicate that the laser energy in the range of 0.815-1.120 J/cm^(2) can achieve significant cleaning effects by using the method of backward cleaning, and there is no damage to thesubstrate. And for the energy of 1.426 J/cm^(2), the obvious thermodynamic damage appears on the cleaning surface.The model of heat conduction and thermal stress between particles and substrate was established, and thecomprehensive effect of laser cleaning on glass surface was analyzed. COMSOL was used for simulation, and theresults showed that a good cleaning effect can be obtained when the laser energy is greater than 0.764 J/cm^(2).When the laser energy is 1.426 J/cm^(2), irreversible thermodynamic damage occurs on the glass surface. Thecomprehensive effect of laser cleaning analyzed by theory is consistent with the experimental results. Therefore,through the analysis and modeling of the comprehensive effect of the interaction process between laser and microand nano particles, the cleaning effect of different acting energies can be accurately predicted, so that the correctlaser cleaning energy can be selected to achieve the ideal cleaning effect.
作者
谢仑靖
何长涛
熊玲玲
宋倩倩
牛富增
张雨阳
韩敬华
XIE Lunjing;HE Changtao;XIONG Lingling;SONG Qianqian;NIU Fuzeng;ZHANG Yuyang;HAN Jinghua(School of Electronic Information,Sichuan University,Chengdu 610064,China;School of Mechanical and Electrical Engineering,Xi'an Polytechnic University,Xi'an 710048,China;Haimu Star Laser Intelligent Equipment(Chengdu)Co.,LTD.,Chengdu 610000,China;School of Aeronautics and Astronautics,Xihua University,Chengdu 610039,China)
出处
《红外与激光工程》
北大核心
2025年第1期67-79,共13页
Infrared and Laser Engineering
基金
四川省科技厅项目(2024YFHZ0153)
西安工程大学博士科研启动基金项目(107020445)
西华大学人才引进经费项目(RX2300000848)。
关键词
激光清洗
激光诱导损伤
热力学效应
多物理场仿真
微纳颗粒
laser cleaning
laser induced damage
thermodynamic effect
multi-physics simulation
micro-nano particles
