Diffraction tomography is a promising label-free three-dimensional (3D) imaging method for transparent samples due to its low phototoxicity. However, it usually requires coherent illuminations and massive measurements, which will, respectively, introduce speckle noises and time-consuming acquisitions, and thus, limit its applications in multicellular dynamic organisms. To address these problems, here we propose a partially coherent and snapshot diffraction tomography method based on light-field microscopy. By incorporating the illumination optical transfer function into the volumetric differential phase contrast model, we obtain a 3D phase stack from the snapshot four-dimensional phase-space measurements. Then a 3D phase-point-spread function is used for 3D deconvolution to achieve computational optical sectioning and enhance the resolution, and finally, we extract 3D refractive-index information from the 3D phase stack. Experiments on freely moving Caenorhabditis elegans are shown accordingly, demonstrating the great potential of the proposed method for label-free 3D imaging of multicellular organisms in vivo at high speed up to the camera frame rate.

• Received 3 January 2021
• Accepted 1 April 2021

DOI:https://doi.org/10.1103/PhysRevApplied.15.044048