Polarization resolved deep ultraviolet microscopy for label free imaging with enhanced nuclei and fiber contrast

Deep ultraviolet (DUV) microscopy is a rapid, label-free imaging technique widely used in biological applications. However, fibrillar structures, which provide crucial insights into tissue organization, are often overlooked. In this work, we introduce a polarization-resolved DUV microscope capable of extracting both nuclear and fiber features. Illumination at 265 nm enhances nuclear contrast, while polarization imaging reveals fiber orientation. Four images are captured sequentially to calculate the linear polarization properties of the tissue medium. To address pixel misalignment between multiple images, we apply adaptive local thresholds to extract valid features for precise registration. The degree of linear polarization and angle of polarization exhibit significant changes as light passes through tissue samples, revealing variations in polarization states. This additional polarization contrast offers a new dimension of analysis, potentially enhancing the characterization of biological tissues.