Polarimetric Techniques for Optical Characterization of Biological Tissues

Polarimetric imaging exploits the vectorial properties of light—its polarisation state—to probe the microstructural and compositional features of biological tissues. Techniques range from point‐scanning polarimetric microscopy to wide‐field imaging and endoscopic modalities. By analysing the change in polarisation—encoded in measurements such as retardance, depolarisation and diattenuation—researchers can infer collagen fibre orientation, cellular morphology and stromal organisation. The Stokes–Mueller formalism provides a rigorous framework: a Stokes vector describes incoming and outgoing polarisation states, while a 4×4 Mueller matrix captures the cumulative transformation imposed by the tissue. Polar decomposition of the Mueller matrix yields constituent parameters that correlate directly with tissue anisotropy, heterogeneity and pathological state. These methods have been applied to ex-vivo and in-vivo specimens to enhance contrast in oncology, guide surgical resection, monitor fibrosis progression and map three-dimensional birefringent structures. Ongoing advances in instrumentation, real-time data processing and tomographic reconstruction promise ever more precise, non-invasive diagnostics and intraoperative decision support.

Research from Nature Portfolio

Recent studies have demonstrated the clinical potential of surgical polarimetric endoscopy for real-time cancer detection. By integrating polarisation filters into an endoscopic imaging system, researchers measured pixel-wise retardance and depolarisation differences between healthy and malignant laryngeal tissues. This approach, termed surgical polarimetric endoscopy, achieved approximately an order-of-magnitude greater contrast than white-light endoscopy, enabling clearer delineation of squamous cell carcinoma margins during transoral laser surgery. Analysis of excised and stained tissue slices confirmed that variations in polarimetric retardance closely reflect the underlying collagen architecture and cellular arrangement, paving the way for polarimetric guidance in a range of otolaryngological procedures.

Polarimetric Techniques for Optical Characterization of Biological Tissues publication trend

The graph below shows the total number of articles in polarimetric techniques for optical characterization of biological tissues across all publications each year (not limited to Nature Index journals).

Technical terms

Stokes vector: A four‐element vector that fully describes the polarisation state of light.

Mueller matrix: A 4×4 matrix that characterises how a sample transforms an incident Stokes vector into an outgoing one.

Retardance: The phase shift introduced between orthogonal polarisation components as light traverses an anisotropic medium.

Depolarisation: The reduction in the degree of polarisation due to multiple scattering or tissue heterogeneity.

Diattenuation: Differential attenuation of orthogonal polarisation components, often arising from absorptive or dichroic structures.

Birefringence: Optical anisotropy manifested as distinct refractive indices along different axes within a medium.

References

1. Surgical polarimetric endoscopy for the detection of laryngeal cancer. Nature Biomedical Engineering (2023).
2. Reconstructing Three‐Dimensional Optical Anisotropy with Tomographic Müller‐Polarimetric Microscopy. Advanced Science (2025).
3. Characterization of Polarimetric Properties in Various Brain Tumor Types Using Wide-Field Imaging Mueller Polarimetry. IEEE Transactions on Medical Imaging (2024).
4. Time-efficient filtering of imaging polarimetric data by checking physical realizability of experimental Mueller matrices. Bioinformatics (2024).