Phase-reduced sensitivity imaging through a thin diffuser

Imaging through scattering media remains a fundamental challenge in optical imaging, particularly in biomedical applications such as endoscopy, particularly in biomedical endoscopy where biological fluids act as thin diffusers that severely degrade image quality. To address this, we introduce a theoretical and experimental framework based on digital off-axis holography with a dual-illumination strategy. Unlike conventional approaches, our method achieves accurate phase reconstruction without requiring prior calibration of the scattering layer. Furthermore, it eliminates the necessity for rear object illumination, enabling operation in a more practical, single-sided geometry. We validate the proposed method through numerical simulations under strong random perturbations and physical experiments. The reconstruction fidelity is evaluated quantitatively, demonstrating robust recovery of the object's phase profile. The novelty of this work lies in its ability to perform high-fidelity phase imaging through thin scattering layers without layers characterization or illumination of the object behind the layers, while also offering potential for integration into multicore fiber-based endoscopes and for extension to optical encryption applications, where the two captured intensity images may be interpreted as an encrypted signal and a decoding key.