Brewster’s angle, also known as the polarizing angle, is the specific angle of incidence at which light striking a surface is perfectly transmitted without reflection — but only for light polarized in the plane of incidence (p-polarized light). At this angle, the reflected light is completely s-polarized (perpendicular to the plane of incidence).
How It Works:
When unpolarized light hits a boundary between two different media (like air and glass), some of it is reflected and some is refracted. At Brewster’s angle, the reflected and refracted rays are at 90° to each other. At this exact angle:
- No p-polarized light is reflected — it all enters the second medium.
- The reflected light is thus completely polarized perpendicular to the plane of incidence.
Significance:
- Used in polarizing sunglasses and optical devices to reduce glare by blocking reflected polarized light.
- Important in laser technology to produce linearly polarized light.
- Helps in understanding wave behavior at interfaces between materials.
Real-World Example:
Light reflecting off water or glass at Brewster’s angle will appear less bright because the glare is reduced due to the absence of one polarization in the reflected light.
Brewster’s angle demonstrates a key interaction between light polarization and material surfaces, deepening our understanding of optical physics and practical applications in glare reduction and photonic devices.