Tensorial Flow of Mosaic Vector Beams in Physical Review Letters

ISC researcher Davide Pierangeli coauthored an insghtful experimental work now published in Physical Review Letters, Measuring the Tensorial Flow of Mosaic Vector Beams in Disordered Media, D. Pierangeli, A. Aiello, and C. Conti, Phys. Rev. Lett. 132, 243801 (2024).


Optical beams with nonuniform polarization offer enhanced capabilities for information transmission, boasting increased capacity, security, and resilience. These beams possess vectorial features that are spatially organized within localized three-dimensional regions, forming tensors that can be harnessed across a spectrum of applications spanning quantum physics, imaging, and machine learning. However, when subjected to the effect of the transmission channel, the tensorial propagation leads to a loss of data integrity due to the entanglement of spatial and polarization degrees of freedom. The challenge of quantifying this spatial-polarization coupling poses a significant obstacle to the utilization of vector beams in turbulent environments, multimode fibers, and disordered media. Here, we introduce and experimentally investigate mosaic vector beams, which consist of localized polarization tesserae that propagate in parallel, demonstrating accurate measurement of their behavior as they traverse strongly disordered channels and decoding their polarization structure in single-shot experiments. The resultant transmission tensor empowers polarization-based optical communication and imaging in complex media. These findings also hold promise for photonic machine learning, where the engineering of tensorial flow can enable optical computing with high throughput.

Decoding vector beams in complex media. (a) Input message encoded in four SOPs (=4). (b) Intensity distribution detected after the scattering medium. (c) Polarization ellipses deciphered from the received image by using the tensorial flow. Scale bar is 200  μ⁢m.