Energy flows of reflected/refracted waves

In summary, the conversation discusses the relationship between the flow of energy of an incident electromagnetic plane wave meeting an interface between two different dielectrics and the sum of the flows of the reflected and transmitted waves in the x-y plane. The conversation also mentions the conservation of energy and the use of Poynting vectors to prove this relationship. However, there is a lack of information on the energy flows in the y-direction and the conversation requests for clarification or references on this topic.
  • #1
fabpan
6
0
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]
 
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  • #2
This link shows an example of a situation where the incident wave meets an interface between 2 dielectrics with different refractive indexes in the Brewster angle.
 

What is reflection and refraction?

Reflection is the bouncing back of a wave when it hits a surface. Refraction is the bending of a wave as it passes through a material.

How is energy affected by reflection and refraction?

When a wave is reflected, its energy remains the same. However, when a wave is refracted, some of its energy is absorbed by the material it passes through.

What determines the amount of energy reflected or refracted?

The angle at which the wave hits the surface, as well as the properties of the material the wave is passing through, determine the amount of energy that is reflected or refracted.

Can energy be lost during reflection and refraction?

Yes, some energy can be lost during reflection and refraction. This is due to absorption by the material the wave is passing through.

How does the wavelength of a wave affect its energy during reflection and refraction?

The wavelength of a wave does not directly affect its energy during reflection and refraction. However, the wavelength can be affected by the material the wave is passing through, which in turn can affect the amount of energy that is reflected or refracted.

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