Dynamics of mesoscopic fluctuations of localized waves

We follow the temporal evolution of mesoscopic intensity fluctuations and correlation in strongly localized samples. We find an initial burst in relative transmission fluctuations in random one-dimensional (1D) samples due to fluctuations in the arrival time of ballistic transmission. Relative fluctuations subsequently rise, then drop to a minimum at a time t_m, after which they increase rapidly in 1D simulations and quasi-1D (Q1D) measurements. For t>3t_m, results in 1D and Q1D samples converge toward predictions of a dynamic single-parameter scaling model. These results reflect the changing number of modes participating appreciably in transmission as the impact of longer-lived modes grows with time delay.