Multi-focus array light spot generation device and method

[0112] In the following, the incident light wavelength λ=532nm, the numerical aperture of the objective lens NA=1.32, and the refractive index n of the oil-immersed substance t =1.518, and the entrance pupil radius R=3mm is taken as an example to design a specific implementation scheme of multi-focus array spot with adjustable polarization direction and spatial position.

[0113] First, the pure phase modulation on the rear focal plane of the objective lens is designed, and its specific generation method mainly includes the following steps:

[0114] Step 41: If image 3 As shown, the entrance pupil corresponding to the back focal plane of the objective lens is equally divided into N sectors with the same area: A 1 、A 2 ...A N-1 、A N , where the vertex of each sector is the center of the entrance pupil, the radius of the sector is the radius R of the entrance pupil, and the central angle of each sector is Wherein N is an even number, selects N=72 in the present embodiment;