中文题目: 多层电介质衍射光栅高功率激光辐照特性研究
外文题目: Research on Characteristic of Multilayer Dielectric Diffraction Grating under High Power Laser Irradiation
作者: 公维超; 郑也; 杨依枫; 何兵; 周军
刊名: 中国激光
年: 2017 卷: 44 期: 5 文章编号：504003
中文关键词:
测量; 光谱合成; 多层电介质衍射光栅; 干涉测量; 光栅衍射特性
英文关键词:

measurement; spectral beam combining; multilayer dielectric diffraction grating; interferometry; grating diffraction characteristic
中文摘要:
多层电介质反射式衍射光栅作为光谱合成系统的核心元件,在高功率激光辐照下的表面形变将导致其衍射特性改变,进而影响系统合成光束质量和衍射效率。搭建泰曼-格林干涉仪探测在高功率激光辐照下衍射光栅表面的干涉条纹,经图像处理及泽尼克多项式拟合实现光栅表面形貌的重建。采用高功率光纤激光辐照加热光栅,测量另一光束经过热畸变光栅后的光束质量和衍射效率演变。结果表明,在高功率激光辐照下光栅表面形变高度分布为高斯型,辐照功率密度3kW/cm~2时,干涉条纹对应区域内的光栅表面在垂直方向上隆起,最大高度为127nm。表面形变引起衍射光束质量因子M~2退化,这种退化主要来自衍射光远场发散角的增大。光栅衍射效率波动幅度小于1.8%。

英文摘要:
Multilayer dielectric diffraction grating is the most important optical element in spectral beam combining system.The surface distortion of grating under high power laser irradiation will change its diffraction characteristic, which will influence the beam quality and diffraction efficiency of the combining system.We establish an experimental setup of Twyman-Green interferometer to measure the interference fringes on the diffraction grating surface,under the high power laser irradiation.Based on the image processing and Zernike polynomial fitting method,the grating surface profile is reconstructed.With the high power laser heating the grating and another laser measuring the beam quality and diffraction efficiency degradation,the results show that the grating surface deformation distribution conforms to Gaussian model,when the irradiance power density is 3kW/cm~2,the maximum distortion is evaluated to 127nm,which leads to the diffraction beam quality factor M~2 degradation.The degradation is mainly due to the increase of angle divergence after diffraction.The change of diffraction efficiency is less than 1.8%,which is basically unchanged.


文献类型: 期刊论文
正文语种: Chinese
收录类别: CSCD
DOI: 10.3788/CJL201744.0504003


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