部分相干光光栅衍射新特性研究

基于Diriehlet边界条件下瑞利一索末菲衍射积分公式，文章推导出了部分相干光光栅衍射场中交叉谱密度的计算表达式，并以高斯一谢尔模型光束为例研究了部分相干光光栅衍射场中光强的空间分布。数值计算发现部分相干光光栅衍射场中存在极值光强的衍射角不随入射点位置改变而改变和衍射场中极大光强的中央有凹陷，且凹陷深度随光束束宽的减小而变大的新特性。最后利用严格电磁场理论比较研究了本文中的结果。

Study the new characteristics of the grating diffraction by the partially coherent beams

Based on the diffraction integral formula of Rayleigh - Sommerfeld under the boundary condition of Diriehlet, the analysis expression of the mutual intensity in the diffracted field of the partially coherent beam through the grating is derived in this paper, and the space distribution of the partially coherent beams＇ grating diffracted intensity with the classic beams of the Gauss - shell beam is studied. The numerical calculation show that the diffracted angle of the extreme intensity does not varied with the moving incident position, and there exist a depression in the extreme intensity central and the depth of the depression increases by the beams width decrease. The conclusions in this paper derived were compared to study by the rigorous theory in end.