Difference Between Diffraction and Interference

In today’s tutorial, we will discuss the Difference Between Diffraction and Interference. The basic difference between diffraction and interference is that diffraction occurs when secondary wavelets generated by the numerous portions of wavefront superimpose with each other. Interference The basic difference between diffraction and interference is that diffraction occurs when secondary wavelets generated by the numerous portions of wavefront superimpose with each other. Interference occurs when light waves coming from two coherent light sources superimpose with each other.

The other difference is that the intensity of bright fringes is the same for interference but not for diffraction. In today’s post, we will have a detailed look at both interference and diffraction and find their differences. So let’s get started with the Difference Between Diffraction and Interference.

Difference Between Diffraction and Interference

Diffraction

• It occurs when moving waves get involved to the hindrance existing in the path of the wave.
• It also defines that wave bends when moving across the body. This phenomenon first time was first discussed in 1660
• This process occurs normally when the wave coming from such a coherent source has a single wavelength.
• It also works for such systems where the medium has a variable refractive index.
• The DVD shoes different colors it is due to diffraction.
• Mirage is also an example of diffraction.
• It used in the hologram process
• This phenomenon occurs when the secondary wavelets superimpose with each other.

• For this process, the intensity of fringes is not similar for all fringes.

• The direction of propagating waves changes when diffraction occurs.
• The width of the fringes is not equal.
• The space between the fringes is not uniform.
• To observe this phenomenon there is a need for obstacles or slit.
• For this process, there is less contrast between maxima and minima.

Interference

• It is the process in which two different waves mix in such a way that gives a wave of another type having some greater or less amplitude to the previous one.
• If waves are produced from a similar medium then constructive interference occurs.
• It is used in different categories of waves like sounds, light radio. Etc.
• The resultant image form from the interface is known as an interferogram.
• For this process, there is no need for an obstacle.
• For this process, the direction propagating wave does not vary when the superimposition occurs.
• The contrast between maxima and minima is good.
• This process occurs when the light waves coming out from two different coherent light sources superimpose.
• Fringe intensity is similar for all fringes.
• The width of the fringes is equal.
• The space between fringes is uniform

• According to this interference is divided into 2 types.
  • Constructive Interference
  • Destructive Interference

Constructive Interference

• Constructive interference occurs when 2 waves having a similar amplitude and phase superimpose with each other and their resultant wave amplitude is larger than the superimposing waves.
• In simple words, the resultant wave will have an amplitude two times the amplitude of superimposing waves.

Destructive Interference

• Destructive Interference occurs when the 2 waves have similar amplitude and opposite phase then their resultant wave have less amplitude than the other 2 superimposing waves.
• When the 2 waves meet they will sum up and cancel each other due to the opposite phase angle.

Diffraction vs Interference

• The difference between diffraction and interference is that diffraction is the bending of a wave about an obstacle and interference is a superposition of two or more waves
• Diffraction occurs when light waves bend around particles in their path. Interference occurs when two waves interact with each other.
• The effect of diffraction is that it disperses light into different colors and interference makes new waves.
• A common example of diffraction is the rainbow and interference is Young’s Double Slit Experiment.

Difference between diffraction and interference

Features of Diffraction

• Diffraction occurs when light passes through slits or bends about corners of obstacles.
• The size of the aperture of the slit must be comparable to the light wavelength
• Diffraction from slit casues a central bright spot.
• There is variable fringe intensity.

Features of Interference

• There is not use of slits for interference.
• The interference casues equal fringe width
• There is a good difference between maxima and minima.
• The intensity of fringes is constantly separating for constructive and destructive interference.

Similarities Between Diffraction and Interference

• Both are wave phenomena
• Both processes work with wavefronts.
• The superposition of waves exists in both diffraction and interference.

Read also

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• Difference between co-channel interference and adjacent channel interference
• 5G vs 5G Ultra Wideband – What’s the Difference?

Faqs:

What is the main difference between interference and diffraction?

• Interference occurs when two light waves meet and mix. It results from two or more light waves coming at the same time. Diffraction occurs when light waves bend over corners at small openings. it results in light waves striking obstacles through a small gap.

That is a detailed post about the difference between diffraction and interference. If you have any queries ask in the comments. Thanks for reading. Have a good day.