Authors: Cao Bo, Huo Yingdong, Cao Huiqun, etc.
Name: Research on 3D single-particle positioning method based on Pancharatnam-Berry phase lens [J]. Laser Journal, 2022(004):043.
Abstract: The existing bifocal axial positioning method for single-particle tracing involves complex optical path with low optical utilization rate. To solve this problem, a 3D single-particle positioning method based on Pancharatnam-Berry phase lenses is proposed. By adding Pancharatnam-Berry phase lens featured by positive and negative dual focal length in the optical path of traditional fluorescence microscopy imaging system, two focal planes can be imaged on one detector at the same time. The lateral (x-y direction) position information of a single particle can be obtained based on the spot image positioning on the focal plane, and the axial (z-direction) position information of a single particle can be obtained based on the spot intensity ratio of the off-focus plane and on-focus plane. In the experiment, Pancharatnam-Berry phase lens with the focal length of ±100 mm is used to locate the 3D position of fluorescent beads at 1 μm, so as to obtain the positioning precision of 10 nm, 9 nm and 22 nm in the x, y, and z directions.