Brewster Angle Calculator Formula
Understand the math behind the brewster angle calculator. Each variable explained with a worked example.
Formulas Used
Brewster Angle
brewster_angle = atan(n2 / n1) * 180 / piVariables
| Variable | Description | Default |
|---|---|---|
n1 | Refractive Index 1 | 1 |
n2 | Refractive Index 2 | 1.5 |
How It Works
Brewster's Angle
At Brewster's angle, reflected light is completely polarized, with the reflected and refracted rays perpendicular to each other.
Formula
theta_B = arctan(n2 / n1)
At this angle, the reflected light contains only the s-polarization (perpendicular to the plane of incidence).
Worked Example
Light reflecting off glass (n=1.5) from air (n=1).
- 01theta_B = arctan(n2/n1)
- 02theta_B = arctan(1.5/1)
- 03theta_B = arctan(1.5)
- 04theta_B = 56.31°
Frequently Asked Questions
What is polarized light?
Light in which the electric field oscillates in a single plane. Unpolarized light oscillates in all directions perpendicular to propagation.
Why do polarized sunglasses reduce glare?
Glare from flat surfaces (road, water) is predominantly horizontally polarized. Polarized sunglasses block horizontal polarization, reducing glare.
Is Brewster's angle used in lasers?
Yes. Brewster windows in laser tubes minimize reflection losses for one polarization, creating a linearly polarized laser beam.
Ready to run the numbers?
Open Brewster Angle Calculator