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Brewster's Angle: Polarization by Reflection

Interactive 3D simulation of Brewster's angle: tilt an unpolarized light beam onto a glass, water or diamond surface, watch the Fresnel reflectance of the s- and p-polarized components diverge, and find the exact angle where the reflected beam becomes perfectly polarized.

Optics & Light3DModerate60 FPS📱 Mobile-adapted⇄ 2D version

This simulator renders the geometry of Brewster's angle in 3D: an unpolarized beam of light strikes a flat dielectric interface, splitting into a reflected beam and a refracted beam whose angles are governed by the law of reflection and Snell's law. Along each beam, oscillating markers trace the two independent polarization components — s-polarized light (electric field perpendicular to the plane of incidence) and p-polarized light (electric field within that plane) — with amplitudes scaled to the real Fresnel reflectance R_s and R_p computed live from the angle of incidence and the refractive index of the lower medium. Sweep the incidence angle or jump straight to Brewster's angle with tan(θ_B) = n₂/n₁ and watch the p-polarized markers on the reflected beam collapse to nothing, the visual signature of the reflected light becoming perfectly linearly polarized — the same physics behind polarized sunglasses cutting glare off water and glass.

⚙ Under the hood

Tilt an unpolarized light beam onto a glass, water or diamond surface and watch the Fresnel reflectance of the s- and p-polarized components diverge until, at Brewster's angle, the reflected beam becomes perfectly polarized.

opticspolarizationFresnel equationsreflectionBrewster angleSnell's law

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install