Quantitative Phase Imaging via Spin‐Hall Differential Microscopy

ABSTRACT Quantitative phase imaging enables non‐invasive acquisition of quantitative phase information from transparent cells, providing a powerful tool for morphological studies of biological samples, extraction of physical parameters, and cellular phenotype analysis. However, existing methods often rely on complex interferometric setups or require multiple axial scans, limiting their practicality. Here, we propose a quantitative phase imaging method based on spin‐Hall differential microscopy. By adjusting the incident polarization angle, differential operation in arbitrary directions can be achieved. Complete phase gradient information can be extracted by combining differential and biased imaging. Finally, the quantitative phase distribution of the sample can be reconstructed via the least‐squares method. Experimental results validate the efficacy of this scheme in transparent phase targets, label‐free cell imaging, and surface topography detection, exhibiting excellent phase reconstruction accuracy and high‐contrast imaging capability. The scheme features a simple structure, low cost, good stability, and compatibility with various wavelengths, which offers an effective way for quantitative phase microscopy with important applications in biomedical imaging and precision measurement.