High-resolution 3D refractive index microscopy of multiple-scattering samples from intensity images

TL;DR

This paper introduces a novel computational 3D refractive index microscopy technique that reconstructs high-resolution, multiple-scattering biological samples from intensity images, overcoming limitations of traditional interferometric methods.

Contribution

The authors develop a new multi-slice beam propagation method for 3D RI reconstruction from intensity-only data, enabling imaging of complex, multiple-scattering samples with high resolution.

Findings

Successfully reconstructed 3D RI of biological samples including cells and worms.

Achieved lateral resolution of 250 nm and axial resolution of 900 nm.

Demonstrated robustness to multiple scattering in biological imaging.

Abstract

Optical diffraction tomography (ODT) reconstructs a samples volumetric refractive index (RI) to create high-contrast, quantitative 3D visualizations of biological samples. However, standard implementations of ODT use interferometric systems, and so are sensitive to phase instabilities, complex mechanical design, and coherent noise. Furthermore, their reconstruction framework is typically limited to weakly-scattering samples, and thus excludes a whole class of multiple-scattering samples. Here, we implement a new 3D RI microscopy technique that utilizes a computational multi-slice beam propagation method to invert the optical scattering process and reconstruct high-resolution (NA>1.0) 3D RI distributions of multiple-scattering samples. The method acquires intensity-only measurements from different illumination angles, and then solves a non-linear optimization problem to recover the sample 3D RI distribution. We experimentally demonstrate reconstruction of samples with varying amounts of multiple scattering: a 3T3 fibroblast cell, a cluster of C. elegans embryos, and a whole C. elegans worm, with lateral and axial resolutions of 250 nm and 900 nm, respectively.