多层介质膜光谱调制反射镜的反应离子束刻蚀误差容限  

Tolerance of ion beam etching on multilayer dielectric thin film reflector for spectrum reshaping

作　　者：李铭[1,2] 张彬[1] 戴亚平[2] 王韬[2] 范正修[3] 

机构地区：[1]四川大学电子信息学院,成都610064 [2]中国工程物理研究院上海激光等离子体研究所,上海201800 [3]中国科学院上海光学精密机械研究所,上海201800

出　　处：《强激光与粒子束》2009年第5期761-766,共6页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目;四川省青年科技基金项目(05ZQ026-013);教育部新世纪优秀人才支持计划项目(NCET-05-0784)

摘　　要：在千焦拍瓦高功率放大系统设计中,激光脉冲的时空和光谱整形技术一直受到人们的广泛关注。利用反应离子束刻蚀等微纳超精细加工而成的多层电介质结构反射镜可在高功率条件下实现啁啾脉冲的光谱整形。在光谱整形介质结构反射镜的设计与制造中,需要根据要求的反射率来合理提出反应离子束刻蚀误差容限指标。推导出反应离子束刻蚀误差容限的解析表达式。针对神光Ⅱ千焦拍瓦高功率放大系统设计中提出的多层介质光谱调制反射镜,分析了调制结构反射镜各层加工的容许误差,确定了反应离子束刻蚀误差容限指标。研究表明:刻蚀高折射率介质的加工误差容限为35 nm;刻蚀低折射率介质的加工误差容限为62 nm。此外,还从使用需要和加工难易的角度,对刻蚀方案进行了讨论。就加工难易程度而言,优选反应离子束刻蚀方案,且采用刻蚀并残留低折射率介质的方案更容易实现。Lots of attentions have been paid to spatial distribution, temporal profile, as well as spectrum reshapings in the design of kilojoule petawatt chirped pulse amplification（CPA） systems. The muttilayer dielectric thin film reflector fabricated by top-down nano-fabrication processes can be used to realize the spectral reshaping of high power chirped pulses. In the design and fabrication of the reflector, it is necessary to determine the tolerance of ion beam etching appropriately based on the designed refleetivity. Therefore, the analytical expression for the tolerance of ion beam etching has been derived for the multilayer dielectric thin film reflector for spectral reshaping of the chirped pulse laser in the large energy and high power Nd：glass CPA system. The error limitation of ion beam etching for each film has been analyzed, and the tolerance of ion beam etching for the multilayer dielectric thin. film reflector has been proposed. Study shows that： etching high refractive index material layer, the etching tolerance is 35 nm; for low refractive index one is 62 nm. Furthermore, according to application requirement and fabrication capability, etching methods have also been discussed. For the ease of processing, reactive ion beam etching is preferred especially with the scheme of etching and leaving low refractive index media.

关 键 词：光学器件 光谱整形 多层介质膜光谱调制反射镜 微纳超精细加工 误差容限 

分 类 号：O436[机械工程—光学工程]