2016/06/30 by Amaury Badon, Dayan Li, Geoffroy Lerosey +4
Medicine · Physics and Astronomy · #Characterization (materials science) #Diffusion #Digital Holography and Microscopy #Halo #Image resolution #Light scattering #Multiangle light scattering #Optical Imaging and Spectroscopy Techniques #Photon diffusion #Point (geometry) #Point spread function #Random lasers and scattering media #Scattering #physics.optics
paper · pdf · doi:10.1364/optica.3.001160
published as Optica 3, 1160-1166 (2016) · 11 pages, 8 figures
openalex created_date 2016/07/22 · openalex publication_date 2016/10/20 · arxiv created 2016/10/21 · arxiv updated 2016/10/24 · openalex updated_date 2026/08/06
Imaging the propagation of light in time and space is crucial in optics, notably for the study of complex media. We here demonstrate the passive measurement of time-dependent Green's functions between every point at the surface of a strongly scattering medium by means of low coherence interferometry. The experimental access to this Green's matrix is essential since it contains all the information about the complex trajectories of light within the medium. In particular, the spatio-temporal spreading of the diffusive halo and the coherent backscattering effect can be locally investigated in the vicinity of each point acting as a virtual source. On the one hand, this approach allows a quantitative imaging of the diffusion constant in the scattering medium with a spatial resolution of the order of a few transport mean free paths. On the other hand, our approach is able to reveal and quantify the anisotropy of light diffusion, which can be of great interest for optical characterization purposes. This study opens important perspectives both in optical diffuse tomography with potential applications to biomedical imaging and in fundamental physics for the experimental investigation of Anderson localization.