Three-dimensional spatial multi-point uniform light focusing through scattering media based on feedback wavefront shaping*

Abstract

We use feedback wavefront shaping technology to realize the multi-point uniform light focusing in three-dimensional (3D) space through scattering media only by loading the optimal mask once. General 3D spatial focusing needs to load the optimal mask multiple times to realize the spatial movement of the focal point and the uniformity of multi-point focusing cannot be guaranteed. First, we investigate the effects of speckle axial correlation and different axial distances on 3D spatial multi-point uniform focusing and propose possible solutions. Then we use our developed non-dominated sorting genetic algorithm suitable for 3D spatial focusing (S-NSGA) to verify the experiment of multi-point focusing in 3D space. This research is expected to have potential applications in the fields of optical manipulation and optogenetics.