A plane electromagnetic wave is incident at angle theta to the normal on the boundary plane separating two non-magnetic media with relative permitivities e1 and e2. For the case in which the electric vector is in the plane of incidence, show that any wave reflected from the boundary has the same frequency as the incident wave. Show also that the angle of reflection is equal to the angle of incidence.

Derive an expression for the power reflection coefficient in this case and show that there is total transmission through the boundary at one particular value of the angle of incidence (the Brewster angle).