SACE Stage 2 Physics — Light & Atoms 3.1

Polarisation

Unpolarised light has its electric field oscillating in every direction perpendicular to the beam. A linear polariser only lets through the component along its transmission axis, dropping the intensity to I₀ / 2. After that, each further polariser applies Malus's Law: I = I_in cos²Δθ, where Δθ is measured between adjacent axes. Switch filters on, rotate them, and see what comes out the other end.