Interference pattern after the region of the interference

[valeriy2222]

Hi,

I'm concerned about one question about light interference.
It's said that light energy is redistributed during interference. That creates pattern. One slit or double slit interference create maximums and minimums on the screen where the interference takes place.

Now imagine a situation (look at the picture) where two beams interfering with each other under a certain angle and we have the region of interference (region A). Further down along the beams we have screens (B and C). Each of the screens placed in a way that one screen receives the light coming from one slit.

Being in the region of interference (region A) the beams should form an interference pattern thus redistributing the beams energy. The question is whether any pattern will be seen on screens A and B when the beams leave the interference region (consider uniform intensity distribution when the beams leave the slits).

[URL]http://img4.immage.de/2605940456untitled.png[/URL]
(Different colors represent nothing expect a better look)

 

[Disconnected]

Well, they will show single slit interference.

But it seems like you might be asking what lasting effects the interference has on the light beams. There is none. Interference effects waves only at the point where the interference takes place. There is no way to tell if a wave has been previously interfered with.

 

[valeriy2222]

The redistribution of energy takes place during interference. Energy from a place of a destructive interference goes to a place of a constructive interference.

[PLAIN]http://goldberg.lbl.gov/img/interference_pattern.jpg


At these black spots there are no energy since it is redistributed to the white spots. In other words, no moving waves exist at the black spots, and therefore the pattern should remain even when a wave leave the interference region.

I speak about interference case. Do not think about beams having different frequencies or anything else.

 

[valeriy2222]

I ask that question because I found an article written in 2005 where such experiment was done. The only thing that it was performed with microwaves (3cm) and not the light waves which should not really make any difference. They came to the result that it saves some kind of the pattern even when waves do not cross each other.

[URL]http://img6.immage.de/270595034untitled.png[/URL]

The article is "Redistribution of Energy in Electromagnetic Wave Interactions"
Sri Lankan Journal of Physics, Vol. 6 (2005) 51-64
http://www.ip-sl.org/sljp/v6/sljp-v6-6.pdf

 

[ZealScience]

If there is really no light from the other slit then it's simply diffraction pattern (same as single slit). But why there is no light from the other source? If it is exhibiting single slit diffraction, then there is light originated from the othersource, the only posibility is that the distance between slits is very big and distance between slit and screen is also huge. Then the photons come from the other slit is so few that it canbe neglected.

 

[valeriy2222]

If there is really no light from the other slit then it's simply diffraction pattern (same as single slit). But why there is no light from the other source? If it is exhibiting single slit diffraction, then there is light originated from the othersource, the only posibility is that the distance between slits is very big and distance between slit and screen is also huge. Then the photons come from the other slit is so few that it canbe neglected.

They made the radiation go like it shown on the picture.



I personally think that the redistribution takes place and the pattern remains, but due to the wave divergence and small distances between maximums and minimums the pattern disappears quickly.