Metasurface polarimeter and experimental results. A schematic of the metasurface grating beam path (above), where the input beam is incident on a beam splitter. The light is reflected onto a metasurface designed to split the incoming light into 6 different diffraction orders with intensities that depend on the incoming polarization state. These diffraction orders are collimated and focused by a planoconvex lens on the opposite side of the beam splitter before being measured by a camera sensor. Below the schematic are measurement results when using the metasurface polarimeter to analyze light scattering in a tissue phantom. The color map to the right is the degree of polarization (DOP) for light scattered from different points on the tissue phantom, while the magenta, green and blue squares indicate the measurements where the state of polarization has been plotted on the Poincare sphere to the left. The DOP and polarization state can be used to distinguish parts of the tissue with different scattering properties.
Paul Thrane et al./CC BY
A newly developed metasurface-based polarimeter may help move polarization imaging out of specialized optics labs and into routine diagnostic workflows. Reported in Light: Advanced Manufacturing, the technology offers a label-free method for analyzing cancerous tissue—potentially reducing reliance on staining and subjective interpretation in histopathology.
The approach builds on earlier work from the Aston-Oulu research team, which showed that healthy and malignant tissues scatter light differently, altering its polarization state in distinct ways. By measuring these changes, researchers can identify structural differences associated with cancer without traditional sample preparation.
For clinical laboratories, this could translate to faster processing and improved consistency. Polarimetric mapping can also highlight tissue features that remain invisible under conventional microscopy, expanding the diagnostic information available from a single sample.
From benchtop systems to deployable tools
A longstanding barrier to clinical adoption has been the size and complexity of conventional polarimetry systems. These setups typically depend on rotating optical components and multiple sequential measurements, limiting their practicality in high-throughput environments.
To address this, collaborators at the University of Southern Denmark’s Centre for Nano Optics and SINTEF Digital developed a plasmonic metasurface polarimeter that condenses the entire measurement process into a compact format. The device uses an engineered array of gold nanobricks to split incoming light into six diffraction orders, each corresponding to a specific polarization state.
This design enables simultaneous capture of the full polarization profile—including the Stokes vector and degree of polarization—in a single camera acquisition. By removing moving parts and reducing acquisition steps, the system streamlines operation and improves speed.
The prototype currently has an optical path of about 2 cm, with optimized designs expected to shrink this to roughly 5 mm. Such miniaturization could support handheld diagnostic instruments or integration into endoscopic systems for real-time, in vivo tissue assessment.
Toward routine use in pathology labs
Performance testing with tissue phantoms designed to mimic biopsies containing cancerous regions demonstrated clear differentiation between healthy and malignant areas. After calibration, the system achieved Stokes parameter accuracy within ±2%, indicating reliable measurement capability.
The researchers also outline a path toward further performance gains. Replacing camera sensors with photodiode arrays could increase dynamic range and enable kilohertz-range scanning speeds. In parallel, wide-field imaging approaches may remove the need for point-by-point scanning, further improving throughput.
Together, these advances could make polarization-based confocal microscopy more feasible for routine histopathology screening, particularly in settings where speed and reproducibility are critical.
Supported by the European Union’s Horizon 2020 program, the work contributes to the OPTIPATH initiative’s broader vision of “7D Pathology”—an imaging framework that integrates spatial, spectral, temporal, and polarimetric data to enhance tissue characterization and diagnostic precision.
Note: This news summary was generated by AI based on a published press release, followed by a review from human editors.
