Mode-locked fibre lasers provide a wide range of operational regimes. Most of them are not perfectly stable over evolution time. In this talk we discuss approaches to experimentally study in real-time the spatio-temporal intensity dynamics and spectral dynamics of fibre lasers. We demonstrate a wide range of spatio-temporal generation regimes in passively mode-locked lasers, including rogue wave generation captured in spatio-temporal domain. We show as well the experimental existence of dynamic spectral regimes in fundamentally mode-locked fibre lasers via real-time heterodyne-based spectral measurements, and discuss the ways to restore the instantaneous complex field amplitude of the radiation.