High-fidelity single-shot quantitative differential phase microscopy using a pseudothermal Sagnac interferometer

In this Letter, a high-fidelity single-shot differential quantitative phase microscopy (dQPM) method is presented to effectively image nearly transparent biological samples. The proposed method is based on a common-path Sagnac interferometric configuration, which provides superior temporal phase stability and robustness against environmental disturbances. The proposed system exploits a pseudothermal source to achieve high spatial sensitivity and generate dense interference fringes for effective single-shot differential quantitative phase imaging. The effectiveness of the proposed system is experimentally demonstrated with various samples, including silica microspheres, a USAF phase target, fixed and live HeLa cells, and mouse kidney tissue.