Focal Shift and Focal Switch of Polychromatic Vector Gaussian Schell-model Beams
多色矢量高斯-谢尔模型光束的焦移和焦开关

Starting from the propagation equation of the cross-spectral density matrix, a detailed study of the focal shift and focal shift of polychromatic vector Gaussian Schell-model beams passing through a system with the aperture and lens separated is performed. It is shown that before inserting a polarizer the focal shift appears,there is no focal switch,and after inserting the polarizer the focal switch can take place. By rotating the polarization angle the behavior of the focal switch can be controlled.