Transient imaging is an all-optical gating technique that captures the
evolution of the spatial profile of diffusing light with sub-picosecond
resolution, in transmission or reflection and with polarization
sensitivity. Combining the temporal, spatial and polarization domains
gives access to transport quantities that remain hidden to any of them
taken alone: the tensor diffusion coefficient of structurally
anisotropic media, and the early-time depolarization dynamics that
reveal single-scattering properties even deep in the diffusive regime.
The same observables also offer a route to three-dimensional Anderson
localization of light, since the transverse spreading of the transmitted
pattern is a direct signature of the diffusive-to-localized transition
and, unlike time-of-flight measurements, is insensitive to homogeneous
absorption and fluorescence. I will show preliminary measurements on
metallic and high-index dielectric scattering media, with the prospect
of extending it to amorphous correlated dielectric networks.