中国激光, 2006, 33 (3): 34, 网络出版: 2006-04-20
光谱色散平滑的实验研究
Experimental Study of Smoothing by Spectral Dispersion
激光技术 光谱色散平滑 激光辐照均匀性 色循环 laser technique smoothing by spectral dispersion laser irradiation uniformity color cycle
摘要
为提高国内惯性约束聚变(ICF)装置的焦斑平滑能力,在对光谱色散平滑(SSD)技术理论分析的基础上,开展相关实验并研究其平滑机制。实验结合另一种焦斑平滑技术——分布式相位板(DPP)比较分析光谱色散平滑技术应用下的焦斑均匀性的变化。实验表明,利用光谱色散平滑技术中的正弦相位调制对光谱展宽并色散后,在色散方向上的焦斑均匀性有明显改善,120 μm内的光强调制被平滑,其平滑能力依赖于光谱色散平滑技术参量的选择;焦斑的低频光谱强度变化很小,但中高频光谱强度下降,焦斑质量有良好的改善,焦斑的不均匀性从40%降低到12.5%。结果还表明,光谱色散平滑技术中的关键是色循环的产生,光谱本身加宽产生的平滑作用非常有限。
Abstract
To improve the ability of beam smoothing in the device of inertial confinement fusion (ICF) in China, the theory of smoothing by spectral dispersion (SSD) is studied, and some experiments are carried out to analyze the mechanism of SSD in contrast with another technology of smoothing—distributed phase plane (DPP). It is found that the uniformity of focal spot in direction of dispersion is improved markedly using sinusoidal phase modulation (PM) and dispersion in SSD. And the intensity modulation of focal spot in this direction is smoothed by SSD. According to the experiments results, the changes of spectral intensity of spatial frequency at low-mode are very limited, and at high-mode are obviously; the nonuniformity varies from 40% to 12.5%. The ability of smoothing depends on the parameter of SSD. It also shows that the color cycle is very important in the process of smoothing, although the smoothing by broaden of laser spectral width for PM is poor.
周申蕾, 朱俭, 李学春, 林尊琪, 戴亚平. 光谱色散平滑的实验研究[J]. 中国激光, 2006, 33(3): 34. Shenlei Zhou, Jian Zhu, Xuechun Li, Zunqi Lin, Yaping Dai. Experimental Study of Smoothing by Spectral Dispersion[J]. Chinese Journal of Lasers, 2006, 33(3): 34.