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Light through a slit

  1. May 14, 2015 #1
    Why is it that when you shine a laser through a slit, it has the pattern that it does!
     
  2. jcsd
  3. May 14, 2015 #2
    What kind of laser?

    What kind of slit?

    What kind of pattern?

    When I shine a laser pointer through a 1cm slit it makes a single dot pattern on the wall, as expected.

    I suspect you are asking about the double slit experiment, or some kind of spectral scattering through a grid of slits though.
     
  4. May 14, 2015 #3
    A pattern like the one in the image I attached created when a laser shines through a small slit.
     

    Attached Files:

  5. May 14, 2015 #4

    jtbell

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    Staff: Mentor

    The light waves passing through different parts of the slit interfere with each other, and the result is that pattern. Here's an overview:

    http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/sinslitd.html#c1

    And here's a graphical method for calculating the intensity pattern:

    http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/sinint.html#c1

    You can also use integral calculus to calculate it:

    http://en.wikipedia.org/wiki/Fraunhofer_diffraction_(mathematics)#Solution_by_integration
     
  6. May 14, 2015 #5
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