Question

How is linearly polarised light obtained by the process of scattering of light. Find the Brewster angle for air – glass interface, when the refractive index of glass = 1.5. 

Answer 1

Polarisation by Scattering:

When a beam of light passes through a medium, it gets scattered from the particles constituting the medium, provided the size of the particles is of the order of the wavelength of the light. The scattered light, viewed in a direction perpendicular to the direction of the beam of light, is found to be plane polarised. It gives us a method to produce plane polarised light by scattering.

When light is incident at the polarising angle at the interface of a refracting medium, the refractive index of the medium is equal to the tangent of the polarising angle.

`mu=tanp`

Here,

μ → Refractive index of the refracting medium

p → Polarising angle

Given, μ = 1.5

Therefore,

tan p = 1.5

p = tan−1 ( 1.5)

p =56.31°