Luo Yamei, Lü Baida
Department of Biomedical Engineering, Luzhou Medical College, Luzhou 646000, China.
J Opt Soc Am A Opt Image Sci Vis. 2010 Mar 1;27(3):578-84. doi: 10.1364/JOSAA.27.000578.
The closed-form expression for the free-space propagation of superimposed Laguerre-Gaussian beams beyond the paraxial approximation is derived, and the composite polarization singularities formed by the transverse and longitudinal electric-field components are studied in detail. It is shown that there exist composite C-points and L-lines in vector nonparaxial fields. By suitably varying a control parameter, such as the off-axis distance, relative phase, or amplitude ratio, the motion, creation, and annihilation of composite C-points may appear, and in the process the sum of topological charge remains unchanged. The shift, deformation, combination, and disappearance of composite L-lines may take place. The topological relationship holds true. The results are compared with the previous work.
推导了非傍轴近似下叠加拉盖尔 - 高斯光束自由空间传播的闭式表达式，并详细研究了由横向和纵向电场分量形成的复合偏振奇点。结果表明，在矢量非傍轴场中存在复合C点和L线。通过适当改变控制参数，如离轴距离、相对相位或振幅比，复合C点可能会出现运动、产生和湮灭，并且在此过程中拓扑电荷的总和保持不变。复合L线可能会发生移动、变形、合并和消失。拓扑关系仍然成立。将结果与先前的工作进行了比较。
