One more question about Young's double slit experiment

[ErectusX]

Hi,

I would like to know what would happen if we altered one of the slits by making it into a very very long tunnel (an optical cable that would run for a significant distance, but would come out on the other side of the screen almost in the same spot of its beginning).

Would this destroy the experiment, or would it 'slow down' the photon passing through the 'tunnel' slit?

 

[neu]

so are you saying that you are looping the optical fibre round so it's end is it's beginning which is where the slit was?

If I understand you correctly all you are doing is introducing a path difference

A requirement of the double slight experiment is that the indicent wave is coherent and monochromatic so regardless of what happens before the slits, as long as the phonons just before the slits fulfil this criteria then an interference pattern will occur.