Question

Explain how an unpolarised light gets polarised when incident on the interface separating the two transparent media.

Answer 1

When an unpolarized light falls on the interface separating two transparent media, mostly only those electric vectors get reflected at the boundary which is oscillating along a direction perpendicular to the plane of incidence, hence the reflected ray will be polarised containing only electric vectors. The complete polarisation takes place when the reflected wave and the refracted wave are perpendicular to each other.