Electric fields (in red) at the origin of the coordinate axes, as in Figure 2. We see (shown separately) the vectors ${\vec{E}}_i\left(0\right),{\vec{E}}_r\left(0\right),{\vec{E}}_t\left(0\right),{\vec{E}}_i\left(0\right)+{\vec{E}}_r\left(0\right)$ corresponding to the exact time where the incident (${\vec{E}}_i\left(0\right)$) field is maximum. The red dots show the tips of the electric fields for a full time period T. In contrast with Figure 3, now the ellipse in medium “i” is described counterclockwise, while the ellipse in medium “t” rotates clockwise.