$\vec{E}(t, \vec{r}) \rightarrow$ Electric field
$\vec{B}(t, \vec{r}) \rightarrow$ Magnetic field
$\vec{B}(t, \vec{r}) \vec{E}(t) \vec{r}) k=\frac{2 \pi}{\lambda}$
$\omega = 2 \pi \nu$
$\nu \quad \vec{n} $
$\vec{E}$ = $\vec{E}_{0} \cos (k ~\vec{n}. \vec{r} - \omega t)$