Increasing stability for the inverse source problems in electrodynamics

We are concerned with increasing stability in the inverse source problems for the time-dependent Maxwell equations in R^3 , where the source term is compactly supported in both time and spatial variables. By using the Fourier transform, sharp bounds of the analytic continuation and the Huygens principle, increasing stability estimates of the L^2 -norm of the source function are obtained. The main goal of this paper is to understand increasing stability for the Maxwell equations in the time domain.