基于薄膜损伤阈值测试的聚焦光学系统设计  

Design of Focusing Optical System Based on Thin Film Damage Threshold Test

作　　者：刘宝怡 张强 蒋世磊[1] 孙国斌[1] 杨国锋[1] LIU Bao-yi;ZHANG Qiang;JIANG Shi-lei;SUN Guo-bin;YANG Guo-feng(School of Photoelectric Engineering,Xi'an technological University,Xi'an 710021,China;Xi'an North Optoelectronic Science and Technology Defense Co,Xi'an 710021,China)

机构地区：[1]西安工业大学光电工程学院,陕西西安710021 [2]西安北方光电科技防务有限公司,陕西西安710043

出　　处：《光学与光电技术》2025年第1期9-14,共6页Optics & Optoelectronic Technology

摘　　要：为解决聚焦系统因离焦产生的问题,设计了一种薄膜损伤阈值测试的变焦光学系统,通过变焦改变最佳聚焦斑点的尺寸和能量密度的分布,解决了薄膜损伤阈值(LIDT)测试中通过离焦方式的聚焦透镜因激光器能量过高而产生的气爆和“内雕”现象。实验结果表明:所设计的聚焦光学系统,最佳聚焦光斑尺寸可通过变焦调节,随着间距由18.152 mm到6.851 mm,有效聚焦光斑直径由100μm到700μm;光束形态满足高斯分布,激光能量分布符合使用要求,验证了该聚焦光学系统的合理性和有效性,该系统用变焦方式改变焦斑尺寸和能量分布,使最佳聚焦光斑作用于膜系表面,防止在元件内部形成激光损伤,减小薄膜阈值损伤的误判概率,提高了激光损伤阈值测试的准确性,为激光薄膜器件的测试提供了技术支撑。A zoom optical system for thin film damage threshold test is designed to change the size of the optimal focusing spot and the distribution of energy density by zooming,which solves the phenomena of gas explosion and“internal sculpture”in the thin film damage threshold(LIDT)test caused by the focusing lens in the defocusing mode due to the high energy of the laser.Experiments show that the focusing optical system designed in this paper,the optimal focusing spot size can be adjusted by zoom.When the pitch changes from 18.152 mm to 6.851 mm,the effective focusing spot diameter changes from 100μm to 700μm.The beam morphology meets the Gaussian distribution.The laser energy distribution in line meets the use of the requirements.The reasonableness and validity of the focusing optical system are verified.The focusing optics can be adjusted by zoom.The system uses zoom to change the focal spot size and energy distribution.The best focusing spot acts on the surface of the film system.The formation of laser damage inside the component is prevented.The probability of misjudgment of the threshold damage of the film is reduced.The accuracy of the laser damage threshold test is improved.

关 键 词：变焦光学系统 光斑尺寸 高斯分布 激光能量密度 薄膜损伤阈值 

分 类 号：O438[机械工程—光学工程]