激光与光电子学进展, 2015, 52 (7): 072204, 网络出版: 2015-07-06
不同波前畸变对连续相位板焦斑的影响
Influence of Different Distorted Wavefronts on Continuous Phase Plate Smoothing Focal Spot
光学设计 连续相位板 峰谷值 均方根梯度 波前畸变 optical design continuous phase plate peak valley root-mean-square gradient distorted wavefront
摘要
为了提高惯性约束聚变(ICF)系统中的焦斑质量,达到靶面辐照均匀性的苛刻要求,系统需要采用束匀滑技术。由于连续相位板(CPP)能灵活控制焦斑形状,且衍射效率高等自身特点,得到了极大推荐。在实际使用过程中,由于光学系统中的多种因素可能造成激光束波前畸变,这将影响连续相位板的匀滑效果。建立了全频段波前畸变激光束的传输与远场的关系,给出了86%的能量焦斑尺寸与低频波前畸变峰谷值和连续相位板面形峰谷值比值的关系,以及86%能量焦斑尺寸与低频畸变波前的均方根梯度值的关系。根据该关系,可以找到波前控制的范围。
Abstract
In order to improve focal spot quality in inertial confinement fusion (ICF) system, beam smoothing technology is required so as to meet the strict requirements of target surface irradiated. Continuous phase plate (CPP) can control the shape of focal spot easily and has high diffraction efficiency. In practical optical system, beam smoothing results can be influenced since a variety of factors can cause distorted wavefront of laser beam. The relationship between the full spectrum of distorted wavefront and optical field in the far field is given, and it is obtained that the relationship between 86% focal spot size and the ratio of peak valley value of low frequency distorted wavefront and surface shape of CPP. Meanwhile, the relationship between 86% focal spot size and root-mean-square gradient value of low frequency distorted wavefront is also shown. According to the relationship, the range of controlling distorted wavefront can be found.
冯友君, 王忠. 不同波前畸变对连续相位板焦斑的影响[J]. 激光与光电子学进展, 2015, 52(7): 072204. Feng Youjun, Wang Zhong. Influence of Different Distorted Wavefronts on Continuous Phase Plate Smoothing Focal Spot[J]. Laser & Optoelectronics Progress, 2015, 52(7): 072204.