Is There a Real Difference Between Diffraction and Interference in Physics?

This can lead to confusion, but in summary, diffraction and interference are essentially the same phenomenon and the distinction between them is mostly semantic.
  • #1
KFC
488
4
I am reading texts on fundamental physics about diffraction and interference. When comes to diffraction, it takes a single slit as example and using Huygen's principle to explain how the wave transmitt and form the pattern. It sounds like that the pattern is due to interference. One textbook even said that "there is no fundamentaldistinction b/w interference and diffraction ..." It is really confues

1) if there is no difference, why using different terms?
2) whem comes to a pinhole, can I say the resulting airy discs are also come from interference?
3) in Bragg diffraction (2D case), it is all about interference b/w reflected waves, why still call it "diffraction"?
 
Science news on Phys.org
  • #2
You could say diffraction is caused by interference.
I would probably be happy dropping the term diffraction completely and just using interference everywhere.
 
  • #3
One way to think about diffraction is the resultant interference between different spatial modes of the total field. So conceptually, there is no real distinction.

In practice, "interference" usually refers to how a single mode interferes with itself (Mach-Zender interferometers, Young interferometers, etc), while "diffraction" usually refers to the more general case (e.g. diffraction by an aperture)
 

1. What is the difference between diffraction and interference?

Diffraction and interference are both phenomena that occur when a wave encounters an obstacle or passes through an opening, but they are caused by different mechanisms. Diffraction is the bending of waves around obstacles or through openings, while interference is the interaction between two or more waves that results in either constructive or destructive interference.

2. How do diffraction and interference affect the behavior of waves?

Diffraction and interference both cause changes in the amplitude and direction of waves. Diffraction results in the spreading out of waves, while interference can either amplify or cancel out waves depending on the phase difference between them.

3. What is the mathematical representation of diffraction and interference?

Diffraction can be described using the Huygens-Fresnel principle, which states that every point on a wavefront can be considered as a source of secondary spherical waves. Interference can be described using the superposition principle, which states that the total amplitude at a point is the sum of the individual amplitudes of the waves at that point.

4. How are diffraction and interference used in scientific and technological applications?

Diffraction and interference are used in a variety of scientific and technological fields. In physics, they are important in understanding the behavior of light and other waves. In engineering, they are used in the design of antennas, holograms, and other devices. In chemistry, they are used in X-ray crystallography to study the structure of molecules. In everyday life, they are used in technologies such as CD and DVD players.

5. Can diffraction and interference occur simultaneously?

Yes, diffraction and interference can occur simultaneously and are often observed together. For example, when light passes through a narrow slit, it undergoes both diffraction and interference, resulting in a pattern of bright and dark fringes on a screen. This phenomenon, known as single-slit diffraction, is a result of both the diffraction of light around the edges of the slit and the interference between the diffracted waves.

Similar threads

I Calculating Intensity in Single Slit Diffraction Experiments
    • Optics
Replies
17
Views
2K
Single Slit and Diffraction Grating Formulas
    • Optics
Replies
6
Views
5K
What Causes Equal Interference Amplitudes in Light Diffraction Patterns?
    • Optics
Replies
8
Views
1K
Optics : interference and diffraction
    • Optics
Replies
5
Views
2K
'Diffraction' or 'Interference' gratings ?
    • Optics
Replies
5
Views
7K
More slits, farther maxima of interference patterns, why?
    • Optics
Replies
1
Views
1K
What Is the Difference Between Interference and Diffraction?
    • Optics
Replies
6
Views
2K
B Explanation for bright fringes in Single Slit Diffraction
    • Classical Physics
Replies
4
Views
304
Bragg law vs interference equaiton
    • Optics
Replies
5
Views
1K
Abbe theory: diffraction pattern to primary image
    • Optics
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top