(adsbygoogle = window.adsbygoogle || []).push({}); In this topic, I repeat a question I posted in an old topic trying to make it more understandable and hoping to receive some answer.

In case an electromagnetic plane wave meets an interface between 2 different dielectrics, the flow of energy of the incident wave through the xy-plane is equal to the sum of the flows of the reflected and transmitted waves through the same plane. This relation seems intuitive for the conservation of energy.

If [tex]\vec{S}_{I}, \vec{S}_{R}, \vec{S}_{T}[/tex] are the vectors of energy flows (Poynting vectors) of the incident, reflected and transmitted waves, then [tex]\left|\vec{S}_{I}\right|\times\cos{\theta_{I}}=\left|\vec{S}_{R}\right|\times\cos{\theta_{R}} + \left|\vec{S}_{T}\right|\times\cos{\theta_{T}}[/tex].

Many books show how to prove this relation starting from the Maxwell's equations.

Instead,I couldn't find any indication about the flows of energy along the y-direction. Surprisingly for me, in the y-direction it seems that the flow of energy of the incident wave be not equal to the sum of the flows of energy of the 2 resulting waves.Please, could anybody give me some explanation about these energy flows and their relationship or sugest me a reference to a book that deals with them?

[URL]http://einstein1.byu.edu/~masong/emsite/S5Q60/Brewster.gif[/URL]

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Energy flows of reflected/refracted waves

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**