共轴抛物镜线聚焦性能的2维分析

2D analysis of line focus of on-axis parabola

掠入射泵浦方式作为一种全新的X射线激光泵浦方式,采用了共轴抛物镜作为线聚焦器件.利用2维光路追踪程序,计算了高斯光束从5°掠入射角增加到7°时入射到共轴抛物镜上的线聚焦效果.研究发现,掠入射角从5°增加到7°过程中,线聚焦的尺寸随着掠入射角变大,线聚焦长度从6 mm逐渐变长到12mm,线聚焦宽度从150μm变到40μm;掠入射角6.5°～7°可以实现符合实验要求的线聚焦效果,线聚焦尺寸约10 mm×20μm(最小线聚焦宽度),7°掠入射可以实现较好的线聚焦,基本满足实验的要求.

As a novel pumping scheme, the line focus system applied in the grazing incidence is the on-axis parabola. Using 2D ray-tracing program, the line focus effects with different incidence angle of a Gaussian laser pulse were calculated. As the inci- dence angle increases from 5° to 7°, the length of the line focus is improved from 6 mm to 12 mm, and the widthes are varied from 1 5 μm to 4 μm. The results show that the 6. 5 °～ 7°incidence is capable of realizing a well line focus with 1 0 mm× 2 μm to satisfy our experiment.