Single-shot quantitative differential phase contrast microscopy based on support-domain constraint

Differential phase contrast (DPC) microscopy is a powerful non-interferometric quantitative phase imaging (QPI) technique widely used for label-free visualization of transparent specimens under partially coherent illumination. However, its reliance on multi-frame acquisitions to ensure isotropic phase reconstruction inherently limits imaging speed, hindering the observation of fast biological dynamics. Here, we present support-domain-constraint DPC (SDC-DPC), a single-shot, isotropic-resolution QPI method that reconstructs quantitative phase maps from only one raw intensity image. By employing an optimized uniform semi-ring illumination to enhance the uniformity of the phase transfer function and incorporating a spatial support constraint into an iterative reconstruction framework, SDC-DPC compensates for the missing frequency components and suppresses the directional artifacts inherent to single-directional DPC. Simulations and experiments demonstrate that SDC-DPC achieves phase reconstruction accuracy and resolution comparable to conventional four-frame DPC for both static and dynamic samples, while completely eliminating motion artifacts in live-cell imaging. This work establishes a simple yet powerful paradigm that transforms DPC into a single-shot quantitative phase microscopy modality, opening new avenues for label-free imaging of dynamic biological processes.