Hi all, 

Please click on attached files to read question and see figures.

 

Loading weasel words and spherical cows........ done

 

For a perfect fringe pattern, the em field/number of photons in the dark area is 0. (Handwaving: no light there cause it is dark. Mathy: probability function goes to 0 - I think that pattern is sin^2 IIRC) Since there is no light there you can put anything in that region without affecting the light.

 

Adding some reality back in. Only the center of the dark has 0 photons, so you have to use a perfect thread instead of sheet. But, even that is not perfect dark because air diffraction etc. Also, you're right that the sheet must be thinner than the fringe because of edge diffraction and fringe effects. But even given all the caveats, putting anything in the dark region will have a small impact because it's dark there.

 

Now for a more interesting result, put that sheet in the bright areas. Blocking the central bright gives you the same output waveforms, but they will be much dimmer. Blocking other orders of bright fringes will do something, especially if you only block right or left side, but I don't remember what exactly.

 

BTW, cut 'what' beams? You already established that at that plane you have a fringe pattern, aka 'many' beams.

Edited September 25, 20178 yr by Chopsticks
Bad text editor! Bad!

Yes, read about Quantum tunneling, but in classical physics no.

Edited October 2, 20178 yr by Vmedvil