Question

What phenomena can be explained using a wave model of light? Do this carefully and thoroughly. Be sure to state what property of the wave model leads to the explanation it provides. Link this property to the ray and Huygen’s diagrams you draw. DRAW DIAGRAM

Answer 1

There are many phenomenas that can be explained using wave nature of light. Like diffraction and interference.

Interference: The physical effect resulting from overlapping of two or more light waves is known as interference. Interfering light wave compulsorily need to have the same frequency and amplitude. Interference is of two types:

Constructive interference: As a result of this phenomenon the amplitude of the resulting light wave is the sum of the amplitudes of the individual light waves.

Destructive interference: The amplitude of the resulting light wave is less than the amplitude of the individual light waves undergoing destructive interference.

Diffraction: The phenomenon of spreading of light waves when it passes though the corners of an object is known as diffraction.

We require wave nature of light to explain the effect of interference and diffraction as they only explain the patterns formed .

• If we take particle nature of light in interference then will be no path or phase difference between the two occurring photons and hence a continuous illumination will be obtained on the screen and thus no interference pattern will be formed.
• If we consider diffraction of light due to the particle nature (due to photons) the there will be no bending of the wave instead there will be direct collision between the edge and the photon and it’s deflection can be obtained by the equations of mechanics . Hence irregular pattern will be formed which is not the case of diffraction pattern.

Huygens stated that an expanding sphere of light behaves as if each point on the wave front were a new source of radiation of the same frequency and phase.

Reference

http://farside.ph.utexas.edu/teaching/302l/lectures/node150.html

https://thiscondensedlife.wordpress.com/2016/05/21/diffraction-babinet-and-optical-transforms/

https://hemantmore.org.in/foundation/science/physics/interference-light/2040/