An unpolarised beam of light is incident on the surface of a transparent dielectric block placed in air. The reflected beam is found to be completely plane-polarised for a particular angle of incidence.
(i) Define plane-polarised light.
(ii) Describe qualitatively how reflection at the surface of a dielectric can produce plane-polarised light.
(iii) State the condition that must be satisfied by the angle of incidence for the reflected beam to be completely plane-polarised and explain, with a ray diagram, why this condition leads to plane polarisation.