How Does Tilting the Screen Affect the Double Slit Interference Pattern?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 6K views
siifuthun
Messages
24
Reaction score
0
A vertical screen has two narrow slits separated by distance d. A
second screen, parallel to the first, is a distance L away (L>>d) and
displays the first minimum of the two slit interference pattern a height
h above the horizontal line drawn from the center of the slits to the
second screen. What is the smallest angle that the second screen be
tilted to make that minimum become a maximum?

I think that what they're asking for is what angle do we tilt the screen so that a maximum occurs at height h. In that case, if we were to slant the screen towards the slits, would the angle that the second screen is moved be equal to the angle between the two slits? If that's the case, then do we just solve for dsin(theta) = n*lambda?

Or would I need make the distance that these two rays travel equal to 1 wavelength by adding another 1/2 wavelength by slanting the screen?
 
Physics news on Phys.org
siifuthun said:
A vertical screen has two narrow slits separated by distance d. A
second screen, parallel to the first, is a distance L away (L>>d) and
displays the first minimum of the two slit interference pattern a height
h above the horizontal line drawn from the center of the slits to the
second screen. What is the smallest angle that the second screen be
tilted to make that minimum become a maximum?
I think that what they're asking for is what angle do we tilt the screen so that a maximum occurs at height h. In that case, if we were to slant the screen towards the slits, would the angle that the second screen is moved be equal to the angle between the two slits? If that's the case, then do we just solve for dsin(theta) = n*lambda?
Or would I need make the distance that these two rays travel equal to 1 wavelength by adding another 1/2 wavelength by slanting the screen?
I don't see how you would get a maximum at the position of first minima by tilting the screen. To get the first maximum, you would need to make that point on the screen at a greater height above the horizontal line between the centre of the slits to the screen. By tilting it, you will only make it decrease.

AM
 
Andrew Mason said:
I don't see how you would get a maximum at the position of first minima by tilting the screen. To get the first maximum, you would need to make that point on the screen at a greater height above the horizontal line between the centre of the slits to the screen. By tilting it, you will only make it decrease.
AM

Hmm, I don't know, I was a bit confused as to what the professor was asking, he made up this problem and didn't check for any errors before posting it as a practice for the midterm. We're going to go over in discussion today, so maybe that'll help.