Transparency, Secrecy, and Profiling using Mutual Scattering in Complex Media

The research presented in this thesis aims to modulate the incident light into a scattering media to both control and study the light transport inside it inspired by questions from industry. In particular, we study a new phenomenon called mutual scattering, an interference process that modulates the extinction of light. Mutual scattering is always present when multiple light waves are incident into a finite scattering sample, but it was discovered only recently. Mutual scattering has potential applications in optical characterization, transparency modulation, and beyond. We commonly refer to mutual scattering as “wavefront shaping 2.0”, as it is the next step in wavefront modulation.
This thesis presents the first experimental observation of mutual scattering. In addition, we also use the wavefront shaping technique to study how the macroscopic shape of a sample affects light scattering inside it, since the device shape represents a new frontier in mesoscopic physics, inspired by industry. Furthermore, we propose an optical wireless communication based on speckle patterns to increase secrecy, and we test it using speckle correlation and unsupervised classification algorithms.