Taking advantage of multiple scattering for Optical Reflection Tomography

TL;DR

This paper introduces a novel optimization algorithm for 3D reflection-mode optical diffraction tomography that leverages multiply-scattered waves to improve refractive index reconstruction.

Contribution

It presents a new method that utilizes multiply-scattered waves and regularization techniques to address the ill-posed inverse problem in reflection optical tomography.

Findings

Validated with 2D and 3D simulations showing improved performance under weak scattering.

Demonstrated the importance of multi-wavelength analysis for accurate reconstruction.

Showed that simplified forward models can be used for computational efficiency.

Abstract

Optical Diffraction Tomography (ODT) is a powerful non-invasive imaging technique widely used in biological and medical applications. While significant progress has been made in transmission configuration, reflection ODT remains challenging due to the ill-posed nature of the inverse problem. We present a novel optimization algorithm for 3D refractive index (RI) reconstruction in reflection-mode microscopy. Our method takes advantage of the multiply-scattered waves that are reflected by uncontrolled background structures and that illuminate the foreground RI from behind. It tackles the ill-posed nature of the problem using weighted time loss, positivity constraints and Total Variation regularization. We have validated our method with data generated by detailed 2D and 3D simulations, demonstrating its performance under weak scattering conditions and with simplified forward models used in the optimization routine for computational efficiency. In addition, we highlight the need for multi-wavelength analysis and the use of regularization to ensure the reconstruction of the low spatial frequencies of the foreground RI.