Brewster's Law

μ = tan θ_B

At Brewster's angle, reflected light is 100% polarized ⊥ to the plane of incidence.

Live Reflection Simulator — Three Rays Visible

Angle of Incidence (θ): 55°

Refractive Index (μ): 1.50

Brewster Angle θ_B = 56.31°
Polarization: Partially Polarized

Incident — Unpolarised

Reflected — Polarised

Refracted — Transmitted

What Happens?

When unpolarized light hits a surface at Brewster's angle, the reflected ray becomes completely plane-polarized.
Reflected and refracted rays are perpendicular (90°).
Brewster angle depends only on refractive index: θ_B = arctan(μ)
Used in polarizers, laser cavities, anti-glare coatings, photography filters.

Real-World Examples

Polarized sunglasses block horizontally polarized light (glare from roads/water). They work best when you tilt your head ~55–60° — close to Brewster's angle for glass/water!