Characteristics of high reflection mirror with an SiO2 top layer for multilayer dielectric grating
Characteristics of high reflection mirror with an SiO2 top layer for multilayer dielectric grating
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多层介质光栅用SiO2顶层高反射镜的特性
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Z. Fan
中科院分区：
文献类型：
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作者：
Shijie Liu;Yunxia Jin;Yun Cui;Jianyong Ma;J. Shao;Z. Fan
高反镜是制作脉冲压缩器用多层介质光栅的关键，高反镜由具有优良光谱特性和高抗损伤能力的介质叠层构成。选择SiO2材料作为高反镜的顶层，有利于提高MLD光栅的激光损伤阈值，并减小曝光过程中光刻胶中的驻波效应。基于HfO_2四分之一波长（H）和SiO_2半波长（L）的（HLL）_9H设计，得到了MLD光栅高反镜的优化设计，其中SiO_2顶层采用了包含MLD光栅衍射效率和光栅电场增强的评价函数进行优化。详细分析了介质镜制作误差对MLD光栅性能的影响。HR反射镜也是通过电子束蒸发制造的，其在413 nm的曝光波长和1053 nm的工作波长下显示出良好的光谱特性，并且对于12 ns脉冲的平均损伤阈值为10 J cm-2。
The high reflection (HR) mirror composed of dielectric stacks with excellent spectrum characteristics and high damage resistant ability is critical for fabricating multilayer dielectric (MLD) grating for pulse compressor. The selection of the SiO2 material as the top layer of the HR mirror for grating fabrication is beneficial for improving the laser-induced damage threshold of MLD grating as well as minimizing the standing-wave effect in the photoresist during the exposure process. Based on an (HLL)9H design comprising quarter-waves of HfO2 (H) and half-waves of SiO2 (L), we obtain an optimal design of the HR mirror for MLD grating, the SiO2 top layer of which is optimized with a merit function including both the diffraction efficiency of the MLD grating and the electric field enhancement in the grating. Dependence of the performance of the MLD grating on the fabrication error of the dielectric mirror is analysed in detail. The HR mirror is also fabricated by E-beam evaporation, which shows good spectral characteristics at the exposure wavelength of 413 nm and at the operation wavelength of 1053 nm and an average damage threshold of 10 J cm−2 for a 12 ns pulse.