Polarization of Light
Malus's law · Brewster angle · birefringence
Physics: Malus's law: I = I₀cos²θ (intensity after polarizer at angle θ to E-field). Brewster angle: tanθ_B = n₂/n₁ — at this angle, reflected light is perfectly polarized. LCD screens sandwich liquid crystals between crossed polarizers. Birefringence Δn: calcite 0.172, quartz 0.009. Circularly polarized light: E_x = cos(kz−ωt), E_y = sin(kz−ωt) — constant amplitude, rotating direction. Jones calculus: polarization as 2-vectors, optical elements as 2×2 matrices.