Question

When unpolarized light passes from air to a transparent medium, under what condition does the reflected light get polarised?

Answer 1

Unpolarized light:

1. When unpolarized light passes through a transparent medium from the air, then the reflected ray is totally plane-polarized when the refracted rays and the reflected and are perpendicular to each other.
2. The angle of incidence for which we got the reflected light polarised, is known as the polarization angle (that is ${\mathrm{i}}_{\mathrm{p}}$) for that medium.
3. Now suppose that the transparent medium has a refractive index $\mu$, then the relation between polarization angle and refractive index can be given by Brewster’s law, which reads, $\tan \left({\mathrm{i}}_{\mathrm{p}}\right)=\mathrm{\mu }$