Difference Between Diffraction and Interference

In today’s tutorial, we will discuss the Difference Between Diffraction and Interference. The basic difference among diffraction and interference is that diffraction occurs when secondary wavelets generated by the numerous portion of wavefront superimpose with each other. While interference The basic difference among diffraction and interference is that diffraction occurs when secondary wavelets generated by the numerous portion of wavefront superimpose with each other. While 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 Difference Between Diffraction and Interference.

Difference Between Diffraction and Interference

Diffraction

• It occurs when moving waves get involvement 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 discussed in in 1660
• This process occurs normally when the wave coming from such a source that is coherent has single wavelength.
• It also works for such systems where the medium has a variable refractive index.
• The DVD shoes diiffent 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 of having similar amplitude and opposite phase than 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

Diffraction	Interference
It can be caused by obstacles or hoping in the path of the wave	it caused by the interaction of two or more waves
It results in the bending and spreading of waves	It causes the reinforcement or cancellation of waves
It can occur with any type of wave-like light, sound, or water	It occurs with waves of similar type and frequency
it observed in single-wave sources	It needs at least 2 waves sources
It does not need coherent wave sources	It needs a coherent wave source
it can cause any type of wave wavelengths	It mostly noticed with waves of the same wavelengths
It generated a diffraction pattern-like series of bright and dark fringes	It generated interference patterns like a series of bright and dark bands
It can be observed with a simple experiment, like shining a laser through a narrow slit	It needs more  sophisticated experimental setups, that is  double-slit experiment
It used for the study of materials features like crystal structures	It is used for the study of wave features like amplitude and phase
It is affected by the size of the obstacle or opening relative of the wavelength of the wave	It affected by the relative phase and amplitude of waves
It is a fundamental property of wave nature	it occurs due to the superposition of waves
This can occur with waves propagating through a medium, like air or water	This can occur with waves propagating through a medium, for example with electromagnetic waves
it causes one, two, or three dimensions	It exists in two dimensions
it causes the wavefront to change direction	It causes wavefront to vary in amplitude and phase
It occurs in free space or in the existence of a medium	it occurs in free space or in presence of a medium
it is used to manipulate the direction of waves, like  in diffraction gratings	It is used for the creation of interference patterns like in holography
This can cause diffraction of light in the eye, affecting visual perception	It can use for the creation of interference filters in optical applications
It is a factor in the desing of numerous optical system	It is a factor in the design of interferometric systems
it is a common phenomenon in nature, like the diffraction of waves around a seashell	it is a main phenomenon in science such as the interference of light in a Michelson interferometer
This can lead to the cause of complex wave patterns, like in the diffraction of waves through a grating	it used for the creation of accurate  measurements, like  interferometry

 

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.