远场几何光路追踪唯象模型

在激光靶耦合流体模拟程序中,相对于传统几何光路追踪方法,Wigner分布函数光路追踪方法可以描述激光衍射效应;但Wigner分布函数方法需要大量的激光光线来刻画激光能量在相空间的分布,降低了流体计算效率。基于Wigner分布函数方法提出了一个唯象模型,可以用较少的光线刻画宏观特征。该模型将Wigner分布函数分解成坐标空间与相空间两部分函数的乘积,并假定相空间分布函数具有特定的形式。该模型适用于空间相干度较低的实际光束,成功描述了OMEGA激光器光束,并且可以描述经过连续相位板匀滑后的实际光束。

Laser ray-tracing phenomenal model at far field

Wigner distribution function method includes diffractive effects into the conventional ray tracing model of laser beams. However, there are some difficulties when using this method in hydra-dynamics codes. Wigner distribution function method needs a large number of laser rays to describe laser energy distribution in phase space, which results in efficiency reduction in hydra-dynamic simulations. This paper proposes a phenomenal model which is based on Wigner distribution function. This model can describe the macroscopical intensity distribution of practical laser beams on positions at and off the focal spot. And the continuous phase plate (CPP) can also be described in this model.