基于光束扫描的光场匀化技术  

Light Field Homogenization Technology Based on Beam Scanning

作　　者：张海冬 赵成强[2,3] 张益彬 曹红超[2,3] 晋云霞 刘世杰[2,3] 邵建达[1,2,3] Zhang Haidong;Zhao Chengqiang;Zhang Yibin;Cao Hongchao;Jin Yunxia;Liu Shijie;Shao Jianda(School of Microelectronics,Shanghai University,Shanghai 200444,China;Laboratory of Thin Film Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Key Laboratory of Intense Laser Materials,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]上海大学微电子学院,上海200444 [2]中国科学院上海光学精密机械研究所薄膜光学实验室,上海201800 [3]中国科学院上海光学精密机械研究所强激光材料重点实验室,上海201800

出　　处：《光学学报》2024年第16期20-29,共10页Acta Optica Sinica

基　　金：国家重点研发计划(2020YFA0714500);国家自然科学基金(61875212,U1831211);上海市战略性新兴产业发展专项基金(31011442501217020191D3101001);中国科学院国际合作项目(181231KYSB20200040);中国科学院战略性先导科技专项(A类)资助(XDA25020314)。

摘　　要：提出一种新型的光束扫描匀光方法。扫描干涉光刻后基板处的整体光场强度可以实现均匀分布,进而光栅基板处的曝光剂量就可以实现宏观上的均匀分布。对扫描匀光方法的扫描参数进行数值分析,并开展相关实验。扫描匀光的实验结果表明,当步进距离与光斑半径之比小于等于1.2时,经过光束扫描叠加后,基板处的光场均匀性优于99.00%,相较传统高斯截光的方式,均匀性至少提高5%;引入参考光进行条纹漂移锁定控制后,在?200 mm的扫描过程中,光束的相位变化小于±0.015个干涉条纹周期,实现了光束扫描过程中条纹“静止”在基板位置处的效果。Objective As the core instrument for developing ultra-strong and ultrashort laser devices,the load capacity of the holographic grating entirely depends on the effective aperture of the pulse-width compression grating and the anti-laser damage threshold.Large-aperture holographic gratings are currently only available to the United States and Europe,with China facing an embargo.Domestic and international methods such as beam scanning exposure,static interference field transmission exposure,exposure splicing,and mechanical scribing have not been able to manufacture bidirectional meter-level gratings.Recently,researchers have applied large-aperture off-axis reflective collimators to the double-beam exposure system,overcoming the aperture limitations of large-aperture collimating lenses and offering convenient periodic adjustment advantages.Our study paves a new way for fabricating large-aperture diffraction gratings and lays a technical foundation for developing bidirectional meter-level pulse compression gratings required for hundred-petawatt-level high-power laser devices.However,the off-axis reflective exposure system presents an uneven exposure dose issue.Traditional methods address this by employing Gaussian spot center interception to achieve a highly uniform light field,which results in low energy utilization and increased exposure time.The increase in exposure time not only increases the stability requirements of the exposure system but also reduces the efficiency of the production grating.The rise of beam shapers has seen widespread use of schemes that convert Gaussian beams into flat-top beams in Lloyd’s mirror exposure systems.However,after shaping by the beam shaper,the Gaussian beam can no longer filter out stray light and high-order mode interference in the optical path using a spatial filter,affecting grating manufacturing quality.In this study,we propose a novel beam scanning homogenization method based on the existing large-aperture off-axis reflection exposure system.Post-scanning interference lit

关 键 词：光栅 全息光栅 曝光系统 光束扫描 光场均匀性 条纹漂移锁定 

分 类 号：O436[机械工程—光学工程] TN305[理学—光学]