The degree of polarization is a fundamental property of light, yet no technology has previously enabled its programmable modulation across space.

In a study published in Nature, a team from the Department of Physics (Alessandro Petrini, Claudio Conti and Davide Pierangeli) demonstrates the first spatial degree-of-polarization modulator, unlocking a new degree of freedom for photonic information processing. The system creates light with polarization content sculpted into arbitrary spatial shapes, enabling information encoding in the volume of the Poincaré sphere. This unique capability gives rise to “polarization colour”, in which colours correspond to different polarization states rather than wavelengths. By encoding colour images in a single-wavelength laser, the authors demonstrate high-dimensional optical neural networks and multidimensional optical cryptography. The work opens new avenues for high-dimensional optical computing and emerging photonic technologies.

Article: https://www.nature.com/articles/s41586-026-10891-z

Contacts: Davide Pierangeli davide.pierangeli@uniroma1.it