c) Unpolarised light with intensity I0 passes through a dichroic polariser with its transmission axis ˆp aligned with x and then a Quarter Wave Plate (QWP) whose fast
axis is inclined from x by angle θ, as illustrated above.
(i) What polarisation states are transmitted by the QWP for alignment angles:
θ = 0, θ = π/4 and θ = π/2? [4]
(ii) Using the xy co-ordinate system, state the Jones matrix for the QWP when
θ = 0. [1]
(iii) Hence derive expressions for the transmitted Jones amplitude and the transmitted intensity for arbitrary θ. [5]
(iv) The QWP is now fixed at θ = π/4 and its transmitted light is passed through a
Half Wave Plate (HWP) whose orientation is unknown. Find the polarisation
state that emerges from the HWP, and explain why this does not depend upon
its orientation. [4]