从比较两种对称化光学系统出发 ,使用三柱透镜对称化光学系统对像散厄米 -高斯光束作了详细分析 ,研究表明 :对称化光学系统的作用是将像散光束变换为对称化实宗量光束 ;并消去 x- y耦合项。这样 ,当光束继续在自由空间传输时 ,能保持其形状不变。然而 ,有 x- y耦合项的对称化复光束却不具有这种传输不变性。 Starting from the comparison of two kinds of symmetric optical systems, the three-column lens symmetry optical system is used to analyze astigmatic Hermitian-Gaussian beams. The results show that the function of the symmetric optical system is to convert the astigmatic beams into symmetric real Dependent beam; and eliminate the x-y coupling term. In this way, the shape of the beam remains the same as it continues in free space. However, the symmetric complex beam with the x-y coupling term does not exhibit this transmission invariance.