Diffraction vs Interference
Diffraction and interference are two phenomena discussed in physics. Both diffraction and interference are properties of waves which are discussed under waves and vibrations in physics. Diffraction is the bending of waves in the presence of sharp edges whereas interference is the effect of more than one wave at a point on a given time. Both of these phenomena are very important in the understanding of waves and in physics in general. In this article, we are going to discuss what diffraction and interference are, their definitions, the principles of diffraction and interference, and finally the difference between diffraction and interference.
What is Diffraction?
Diffraction is a phenomena observed in waves. Diffraction refers to various behaviors of waves when it meets an obstacle. The diffraction phenomenon is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings. This can be easily observed using a ripple tank or a similar setup. The waves generated on the water can be used to study the effects of diffraction when a small object or a small hole is present. The amount of diffraction depends on the size of the hole (slit) and the wavelength of the wave. For diffraction to be observed, the width of the slit and the wavelength of the wave must be of the same order or nearly equal. If the wavelength is much larger or much smaller than the width of the slit, an observable amount of diffraction is not produced. Diffraction of light through a small slit can be considered as evidence for the wave nature of light. Some of the most famous experiments in diffraction are Young’s single slit experiment and Young’s double slit experiment. The diffraction grating is one of the most useful products based on the theory of diffraction. It is used to obtain high resolution spectra.
What is Interference?
Interference is the phenomenon where two or more waves superimpose to make a resulting motion at a given point in space. Interference is mostly discussed for coherent waves. This is because, for coherent waves, the interference pattern can be described mathematically in a simple way. When two waves of the same amplitude are interfered with each other, the resulting amplitude at the interfering point can vary from zero to twice the amplitude. The main principle behind describing interference is the principle of superimposition. Interference can be observed in every form of waves. Interference is also a wave property. Interference of two waves can be either constructive interference or destructive interference, given that both waves are of the same type and act on the same point in space.
What is the difference between Interference and Diffraction?
• Diffraction is the bending of wave fronts in the presence of sharp edges whereas interference is the property of making a net effect using multiple waves.
• Diffraction requires an obstacle but interference does not.
• The path of the wave stays intact after interference, but diffraction changes the path of the incident wave.