- #1

DoobleD

- 259

- 20

Intensity of the light reaching the screen behind the slits then looks like that :

My questions are :

1 - why is it the diffraction part the envelope of the double slit interference, and not the other way around ?

2 - Is it actually always in this way only ?

I've looked at 5 textbooks (undergrad level) and none of them justifies that. They all say something like :

*the diffraction act as an envelope, and the corresponding equation is the product of both equations for the single-slit diffraction and for the double-slit interference together.*