Two wavelengths, max/min at same angle

  • #1

Homework Statement


Light goes through two slits 40 mm apart. Does an angle exist at which light of wavelength 440nm has a maximum and light of wavelength 660nm has a minimum?


Homework Equations


dsin[tex]\theta[/tex]=m[tex]\lambda[/tex]1 = maximum
dsin[tex]\theta[/tex]=(m+ 1/2)[tex]\lambda[/tex]2 = minimum


The Attempt at a Solution


I solved for sin[tex]\theta[/tex] in each case, so I got:

m[tex]\lambda[/tex]1 = (m+ 1/2)[tex]\lambda[/tex]2

[tex]\lambda[/tex]1 = 660nm
[tex]\lambda[/tex]=440 nm

Now I'm stuck. Both Ms do not have to be the same, right? So do I have to solve for one of the Ms and stick it into an equation I listed in part 2 above? If so, that's a crazy calculation. Thanks!
 

Answers and Replies

  • #2
Redbelly98
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Correct, the m's can be different. But they must both be integers.

Are the slits really 40 mm apart? That's pretty far for an optical double slit setup.
 
  • #3
They're actually 40 nm apart, sorry.
 
  • #4
Redbelly98
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Are you sure it's not 40 μm?
 
  • #5
ah yes you're right
 

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