Category: Our experiments

Supervised single-shot polarimetry in Nature Communications

DOI 10.1038/s41467-023-37474-0

https://www.nature.com/articles/s41467-023-37474-0.pdf

States of light encoding multiple polarizations – vector beams – offer unique capabilities in metrology and communication. However, their practical application is limited by the lack of methods for measuring many polarizations in a scalable and compact way. Here we demonstrate polarimetry of vector beams in a single shot without any polarization optics. We map the beam polarization content into a spatial intensity distribution through light scattering and exploit supervised learning for single-shot measurements of multiple polarizations. We characterize structured light encoding up to nine polarizations with accuracy beyond 95% on each Stokes parameter. The method also allows us to classify beams with an unknown number of polarization modes, a functionality missing in conventional techniques. Our findings enable a fast and compact polarimeter for polarization-structured light, a general tool that may radically impact optical devices for sensing, imaging, and computing.

Launching optical tsunamis against tumor cells

We demonstrate the excitation of giant rogue waves of light inside human pancreatic tumor cells; they can be used for deep light transport and local heating for cancer treatment.

Rogue waves are intense and unexpected wavepackets ubiquitous in complex systems. In optics, they are promising as robust and noise-resistant beams for probing and manipulating the underlying material. Localizing large optical power is crucial, especially in biomedical systems, where extremely intense beams have not yet been observed. We here discover that tumor-cell spheroids manifest optical rogue waves when illuminated by randomly modulated laser beams. The intensity of light transmitted through bio-printed three-dimensional tumor models follows a signature Weibull statistical distribution, where extreme events correspond to spatially-localized optical modes propagating within the cell network. Experiments varying the input beam power and size indicate that rogue waves have a nonlinear origin. We show these optical filaments form high-transmission channels with enhanced transmission. They deliver large optical power through the tumor spheroid, which can be exploited to achieve a local temperature increase controlled by the input wave shape. Our findings shed new light on optical propagation in biological aggregates and demonstrate how extreme event formation allows light concentration in deep tissues, paving the way to using rogue waves in biomedical applications such as light-activated therapies

https://arxiv.org/abs/2303.04553

Measure multidimensional complex and unknown polarization states in a single shot? All you need is machine learning!

https://arxiv.org/abs/2209.05393

Single-shot polarimetry of vector beams by supervised learning

States of light encoding multiple polarizations – vector beams – offer unique capabilities in metrology and communication. However, their practical application is limited by the lack of methods for measuring many polarizations in a scalable and compact way. Here we demonstrate polarimetry of vector beams in a single shot without any polarization optics. We map the beam polarization content into a spatial intensity distribution through multiple light scattering and exploit supervised learning for single-shot measurements of multiple polarizations. The method also allows us to classify beams with an unknown number of polarization modes, a functionality missing in conventional techniques. Our findings enable a fast and compact polarimeter for polarization-structured light, a universal tool that may radically impact optical devices for sensing, imaging, and computing.