3D focusing through highly scattering media using PSF modulation

In this letter, we present an approach to achieve three-dimensional (3D) focusing through highly scattering media. The method combines 3D computer-generated holography (CGH) with point-spread-function (PSF) based wavefront shaping. With a single transmission matrix measurement, CGH-aided PSF engineering enables us to control light volumetrically under multiple scattering. As a proof of concept, generating user-specified 2D intensity patterns and 3D focusing through scattering media were demonstrated. Further, axial scanning of the focus was realized digitally by using a digital micromirror device. Experimentally, our method achieves an axial scanning range ∼20 times larger than that obtained by the memory effect method. Our work is expected to benefit long-range optical trapping and volumetric imaging through highly scattering media.