Electromagnetic Waves

Thus the wave described by (6) and
(11) or (12) is a transverse wave
propagating in the direction n.
Or that E and B are oscillating in a
plane perpendicular to the wave
vector k, determining the direction
of propagation of the wave.
The energy flux of EM waves is described by the real part of the
complex Poynting vector
1 c
S =
2 4π E × H ∗ = 1 c
2 4π
ER × HR + EI ×
HI + i EI × HR − ER ×
HI
where E and H are the measured fields at the point where S is
evaluated. 2
2 Note : we use the magnetic induction H because although B is the applied
induction, the actual field that carries the energy and momentum in media is H.
Electromagnetic Waves