Single Slit Interference: Explaining the Phenomenon

In summary, single slit interference occurs when waves pass through a narrow slit and interfere with each other, creating a pattern of bright and dark fringes on a screen. This phenomenon can happen with various types of waves, such as water ripples, sound waves, and electromagnetic waves. When the slit's width is on the same scale as the wavelength, a single slit diffraction pattern is produced, which can be described using only the waves at the edges of the slit. This results in either a continuous band or a series of bright and dark fringes depending on the width of the slit.
  • #1
wavingerwin
98
0
Single slit interference. ??

Can someone please explain to me about the single slit interference phenomenon?

My teacher said that after passing through the slit, it can be modeled that there are two wave source coming form each end of the "wall" which makes the slit. How can this actually happen?

Diagram:

| |
| |
--- top end of the 'wall'

>>> direction of wave

--- bottom end
| |
| |

And also, does this happen in every wave (e.g water ripples, sound waves) or just electromagnetic wave?

Thanks:smile:
 
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  • #2


The single-slit interference pattern is actually produced by interference among the waves that come from all points across the width of the slit (not just the endpoints). So in order to calculate the details of the interference pattern (i.e. the intensity at each point on the screen) you have to perform an integration. You can find the details in any optics textbook at the intermediate level or above, e.g. Hecht, Pedrotti, Meyer-Arendt, Strong, ...

For calculating only the locations of the minima (zero intensity) you can use a simplified non-calculus argument, which depends on exact cancellation of matched pairs of waves. This leads to a result which can be described using only the waves at the two edges of the slit, if I remember correctly.
 
  • #3


does this happen in every wave (e.g water ripples, sound waves) or just electromagnetic wave?

Furthermore, what if the slit width is exactly the same as the wave's wavelength?
does interference can happen still? Or it only produces a continuous band with a maxima at the center?

Thanks
 
  • #4


Single slit interference requires slits larger than a wavelength. Like jtbell states, a rough approximation is to consider that the wavelets passing though the middle of the slit are unperturbed, it is only the wavelets at the edges of the slit that will diffract and be the main contributors to an interference pattern. Once the slit's width becomes on the order of or smaller than the wavelength then you will reproduce a single slit diffraction pattern.
 
  • #5


Once the slit's width becomes on the order of or smaller than the wavelength then you will reproduce a single slit diffraction pattern.

By "a single slit diffraction pattern" does it mean it produces a continuous band or a series of bright and dark fringes?

thanks
 

1. What is single slit interference?

Single slit interference is a phenomenon that occurs when a wave, such as light or sound, passes through a narrow opening or slit. The wave spreads out and produces a pattern of bright and dark fringes on a screen placed behind the slit.

2. How does single slit interference occur?

Single slit interference occurs due to the superposition of waves from different parts of the slit. As the waves overlap and interfere with each other, they create a pattern of constructive and destructive interference, resulting in the bright and dark fringes.

3. What factors affect the pattern of single slit interference?

The pattern of single slit interference is affected by the wavelength of the wave, the width of the slit, and the distance between the slit and the screen. A smaller wavelength and wider slit will result in a wider pattern, while a larger distance between the slit and the screen will result in a narrower pattern.

4. What is the difference between single slit interference and double slit interference?

In single slit interference, the wave passes through a single narrow opening, while in double slit interference, the wave passes through two narrow openings. This results in a more complex pattern of bright and dark fringes in the case of double slit interference.

5. How is single slit interference used in practical applications?

Single slit interference is used in various applications such as in the production of holograms, in spectroscopy to study the properties of light, and in diffraction gratings to separate different wavelengths of light. It is also used in the Michelson interferometer, a device used to measure small changes in distance.

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