中文题目: 透射衍射光栅内全反射级次
外文题目: Total internal reflection orders in transmission grating
作者: 邬融; 田玉婷; 赵东峰; 李大为; 华能; 邵平
刊名: 物理学报
年: 2016 卷: 65 期: 5 文章编号：54202
中文关键词:
衍射光栅; 全内反射; 光束取样光栅; 鬼像
英文关键词:
diffraction grating; total internal reflection; beam sampling grating; ghost image
中文摘要:
当前高功率激光装置系统中, 国内使用透射式衍射光栅进行光束采样, 国外甚至使用光栅聚焦并同时结合谐波分离和采样功能. 高功率激光辐照下, 除了0级透射打靶光以及目标取样光外, 其他级次衍射光的影响也不可忽视, 可能造成诸如鬼像聚焦破坏、时间脉宽测量不稳定、近远场测量噪声等问题. 尤其是透射衍射光栅内部全反射级次会导致光栅出射一系列规律的衍射花样, 造成上述干扰和危害. 首先理论上针对透射式光栅(包括取样光栅和聚焦光栅)进行了相应的计算和分析, 然后从实验上观察并测量了取样光栅内部全反射级次的现象, 并且结

英文摘要:
In a current high-power laser system, transmission grating has been used to sample, separate and focus laser beam. Under high power laser irradiation, besides the 0-order shooting beam and target sampling beam, the detrimental influence of other diffraction orders should be taken into consideration seriously. These useless orders may damage other nearby optical elements and mechanical devices, disturb and confuse the measurement of time pulse and near/far-field intensity. Especially the total internal diffraction order will lead to some series diffraction patterns, causing the above problems. First, relevant theoretical calculation and analysis are carried out for transmission grating (including beam sample grating and focusing grating), which can predict and indicate these inconspicuous diffraction orders. These orders appear on four receiving screens regularly and periodically, and the periodic distance between them is determined by ray-tracing draft. Second, the phenomenon of total internal reflection order is observed and measured by combining with anti-reflection film. The measured periodic spacings on three screens are 24 mm, 26 mm and 35 mm, respectively. Moreover, energy intensities of these redundant orders are measured finely, which shows that their contrasts or SNRs to 0-order main laser is in a range of 10(-8)-10(-4)). Finally, some appropriate and effective approaches to eliminating or avoiding total internal reflection and other useless orders are proposed and discussed, which include 1) coating by anti-reflection film with pre-deep etching; 2) optimizing the grating design to make redundant orders far from target spot; 3) placing laser scattering or absorbing devices at corresponding position to avoid being damaged by the side-leakage energy and ghost image of total internal reflection and other redundant orders.


文献类型: 期刊论文
正文语种: Chinese
收录类别: SCIEI
DOI: 10.7498/aps.65.054202


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