Complex speckle illumination for quantitative phase imaging

Speckle patterns generated by multimode fibers (MMFs) are often seen as a challenge in imaging, particularly when precise control of illumination is needed [1]. In this work, we focus on a different perspective: speckles from MMFs can be highly beneficial, offering a diversity of random illumination patterns. We turn this complex illumination into a powerful tool for robust and accurate non-interferometric quantitative phase imaging (QPI). QPI is a robust, label-free optical imaging technique used to study transparent or weakly scattering samples, such as biological cells, thin films, and microstructures [2].