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Decoding chirality at the nanoscale with momentum-space polarimetry
Jeeban Kumar Nayak1, Meghna Sarkar2, Siarhei Zavatski2
1Nanophotonics and Metrology Laboratory (NAM), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland. jeeban.nayak@epfl.ch.
Light, Science & Applications
|May 17, 2026
Summary
We developed a new Fourier-domain polarimetry method to characterize nanoscale chiral structures. This technique precisely measures chirality, improving nanodevices and enabling sensitive molecular enantiomer detection.
Area of Science:
- Nanophotonics and Plasmonics
- Chiroptical Spectroscopy
- Metamaterials
Background:
- Nanoscale optical chirality engineering enables advanced light-matter interactions for applications in sensing, microscopy, and quantum technologies.
- Accurate characterization of chiral nanostructures is crucial for designing next-generation nanodevices.
- Existing chiro-optical methods struggle with spatially varying chirality and disentangling different anisotropic responses.
Purpose of the Study:
- To present a novel Fourier-domain polarimetric framework for comprehensive chiro-optical characterization of nanostructures.
- To investigate the chiro-optical responses of plasmonic gammadion nanoarrays.
- To demonstrate the framework's capability for sensitive molecular enantiomer detection.
Main Methods:
- Utilized Stokes-Mueller polarimetry to map scattered light polarization states in momentum space.
- Analyzed momentum-resolved Mueller matrices to quantify circular birefringence and diattenuation.
- Investigated the influence of structural thickness on chiral responses.
Main Results:
- Captured inhomogeneous radiation patterns revealing electromagnetic modes and diffraction features.
- Enabled simultaneous quantification and decoupling of circular and linear anisotropies.
- Demonstrated the framework's sensitivity in detecting subtle chiro-optical signals and its potential for molecular sensing.
Conclusions:
- The Fourier-domain polarimetric framework provides a comprehensive method for characterizing nanoscale chiroptical responses.
- This approach overcomes limitations of conventional techniques, offering insights into complex chiral systems.
- The developed method serves as a sensitive platform for advanced chiral sensing applications, including molecular enantiomer detection.
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