In order to improve the energy efficiency of high power laser system of ICF and use the optical energy sufficiently, converting Gaussian laser beam into uniform beam is important. Meanwhile, the wavefront of the laser beam in the system is also significant because it affects the imaging quality at image surface and the transfer of image in multilevel magnification laser system. Starting from the Jones matrix of spheric lenses, the intensity transmittance distribution of birefringent lenses beam shaping system has been analyzed by transmission matrix. The wavefronts of different polarized states after transmission through beam shaping system are discussed. The effecting factors, such as the distances between lenses, the lens' mechanical deviation from optical axis of system, have been considered. The uniform laser beam can be obtained. In the ninth beamline of 'SG II' device, the static beam filling factor of near field can be improved from 66% to 80% by using the birefringent lens shaping system.

To improve the energy efficiency of the inertial confined fusion (ICF) high\|power laser system and sufficiently use the optical energy, it is important to convert Gaussian laser beam into uniform beam. From the Jones matrix of spheric lenses, the intensity transmittance distribution of birefringent lenses spatial beam shaping system has been analyzed in detail by optical transmission matrix. The shaping effect has been numerically simulated. The choice of the parameters of birefringent lenses is discussed. The factors, which will influence the shaping effect, such as the fabrication error of center thickness, have also been analyzed. In the experiment, the uniform laser beam is obtained. In the ninth beamline of “Shenguang-Ⅱ” device, the static beam filling factor of near field is improved from 66% to 80%.

为了提高惯性约束聚变高功率激光系统的整体效率和充分利用光能,需要将高斯分布的光束整形为空间均匀分布的平顶光束。本文从球面透镜的琼斯矩阵出发,利用光学传输矩阵对双折射透镜组空间光束整形系统进行了理论分析,数值模拟了整形效果,讨论了透镜组参量的选择以及中心加工厚度误差等因素带来的影响,并对该系统进行了实验研究。在实验中,利用该双折射透镜组整型系统实现了光束的均匀化输出。在神光Ⅱ第九路中,在近场静态工作条件下,可将光束填充因子从原来的66%提高到80％。