Question

Describe polarisation of light by reflection. How does degree of polarisation vary

with angle of incidence of light?

Answer 1

Natural light falls on the boundary between two transparent dielectrics. Tangent of the angle of incidence equals the relative refractive index of the second medium relative to the first. Reflected light is completely polarized in the plane perpendicular to the plane of incidence. Refracted light is partially polarized. 

Brewster Law: tan іB = n21 (1),
where іB is Brewster angle, n21 is relative refractive index of the second medium relative to the first.