An observer looks at a patch of clear sky at a scattering angle of from the Sun (the…
PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Optics & Photonics · Polarisation and anisotropic media
Optics and Photonics, Ch Polarisation states, polarisers and the Jones and Stokes calculus
Problem
An observer looks at a patch of clear sky at a scattering angle of 60∘ from the Sun (the angle between the direction of the incident sunlight and the line of sight to that patch). The light reaching the observer has been scattered once by air molecules. The observer's polarising sunglasses have their transmission axis held parallel to the line joining the Sun and the observed patch, i.e. lying in the plane of scattering.
((a)) Using Π(θ)=sin2θ/(1+cos2θ) for singly scattered light, find the degree of polarisation of the light from this patch.
((b)) Predict whether the patch looks relatively bright or dark through the sunglasses in this orientation, and find the fraction of the patch's total irradiance that is transmitted.