Figure 3
From: Time Circular Birefringence in Time-Dependent Magnetoelectric Media
Magnetic field patterns of circularly polarized states (a) B+ and (b) B− in spacetime for a corresponding polarized Gaussian pulse incident onto the time interface t0, whose k spectrum mainly concentrates in the traveling-wave band, namely k0 − ≫ 2/a.
(c) 
of a pulse whose k spectrum mainly concentrates in the non-traveling- wave band, namely 
. In this case, the pulse is nearly trapped while its intensity increases rapidly. The yellow dashed curve and the two light-blue dashed curves trace the center of the pulse and the edges of the pulse respectively. (d) The width (scale of 1 to the original width 2a) and the center velocity of the pulse varying with time.
