How the interference of light changes if there's a lens?

[Luck0]

Suppose we have the Young's experiment with a convergent lens between the slits and the screen. How would the interference fringes change? Sorry about the silly question, but I'm having a hard time with geometrical optics. Thanks!

 

[UltrafastPED]

If the lens is placed after the beams are combined, and before the screen ... then it will make the pattern smaller.

If you use a diverging (negative) lens, then the pattern will be enlarged ... or you can simply move the screen far away, but then the pattern will be dimmer.

The rays from the various image points don't cross each other unless your screen is past the focal point; in that case the pattern will be enlarged.