https://aip.scitation.org/doi/abs/10.1063/5.0006983
A nice demonstration of what you can do with a time resolved imaging system, these are the optical modes arriving out the end of a long optical fibre.
I love the video in our new paper: Observing mode-dependent wavelength-to-time mapping in few-mode fibers using a single-photon detector array
Tanner Lab 