Thanks for your reply.
As your suggestion. I've done the simulation for orthogonal polarized light. but there is still side lope, I am wondering, if the incident light is incoherent, I don't think there is side lope emerged, because there is no interference between incoming rays.
If I set random phase for each rays, in focal region, there is no PSF formed, the instead is homogeneous intensity distribution everywhere, which is not obviously wrong for light focusing. I am thinking maybe for the incoherent light focusing, the wolf's diffraction formula(based on debye approximation) no longer working.
maybe orthogonal polarized light is suitable for simulation of unpolarized light(or random polarized light).
the attachment is the PSF from orthogonal polarized light. I just add the intensity patterns of x-linear and y-linear. I also enclosed one paper which I use for simulate PSF.
Maybe I didn't catch your idea. could you explain to me in detail ?
thank you very much