  We study approximate cloaking using transformation optics for electromagnetic
waves in the time domain. Our approach is based on estimates of the degree of
visibility in the frequency domain for all frequencies in which the frequency
dependence is explicit. The difficulty and the novelty analysis parts are in
the low and high frequency regimes. To this end, we implement a variational
technique in the low frequency domain, and multiplier and duality techniques in
the high frequency domain. Our approach is inspired by the work of Nguyen and
Vogelius on the wave equation.
