Luo Yamei, Lü Baida
Department of Biomedical Engineering, Luzhou Medical College, Luzhou 646000, China.
J Opt Soc Am A Opt Image Sci Vis. 2009 Sep;26(9):1961-6. doi: 10.1364/josaa.26.001961.
On the basis of the vector Rayleigh-Sommerfeld diffraction integrals, the analytical expression for Gaussian vortex beams diffracted at a half-plane screen beyond the paraxial approximation is derived and used to study the polarization singularities formed by the transverse and longitudinal electric field components in the diffracted field. It is shown that there exist C-points and L-lines that depend on the off-axis parameters in the x and y directions, waist width, wavelength, and topological charge of diffracted Gaussian vortex beams, as well as on the position parameter. By a suitable variation of the off-axis and position parameters, the creation, motion, and annihilation of polarization singularities may take place, and the topological relationship holds true. Therefore, the nonparaxial beam diffraction and propagation provide a method for generating polarization singularities.
基于矢量瑞利 - 索末菲衍射积分，推导了高斯涡旋光束在傍轴近似之外的半平面屏幕上衍射的解析表达式，并用于研究衍射场中横向和纵向电场分量形成的偏振奇点。结果表明，在衍射高斯涡旋光束的x和y方向的离轴参数、束腰宽度、波长、拓扑电荷以及位置参数的作用下，存在C点和L线。通过适当地改变离轴和位置参数，偏振奇点可能会产生、移动和湮灭，并且拓扑关系成立。因此，非傍轴光束衍射和传播提供了一种产生偏振奇点的方法。
