Brewster's Angle — Reflectance Curve & Polarization Oscilloscope (2D)

This 2D companion to the 3D Brewster's-angle simulator visualizes the same Fresnel-equation physics through two abstract 2D representations instead of a ray-tracing scene. The top panel plots the full power-reflectance curves R_s(θ) and R_p(θ) for the s- and p-polarized components of an unpolarized beam across every angle of incidence from 0° to 90°, computed live from Snell's law and the Fresnel amplitude coefficients for the current refractive index — with the p-polarized curve visibly crossing exactly zero at Brewster's angle, tan(θ_B) = n₂/n₁. The bottom panel renders an oscilloscope-style waveform of the reflected beam's s- and p-field oscillations, their amplitudes scaled by √R_s and √R_p, so the p-trace collapses to a flat line precisely when the angle-of-incidence marker crosses θ_B on the curve above. Sweep the incidence angle or jump straight to Brewster's angle to see both the frequency-domain reflectance curve and the time-domain field trace agree on the same physical moment: the reflected light becoming perfectly linearly polarized — the effect behind polarized sunglasses cutting glare off water and glass.