Brewster Angle Calculator Formula

Understand the math behind the brewster angle calculator. Each variable explained with a worked example.

Use the Brewster Angle Calculator

Formulas Used

Brewster Angle

brewster_angle = atan(n2 / n1) * 180 / pi

Variables

VariableDescriptionDefault
n1Refractive Index 11
n2Refractive Index 21.5

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).

n1 = 1n2 = 1.5
  1. 01theta_B = arctan(n2/n1)
  2. 02theta_B = arctan(1.5/1)
  3. 03theta_B = arctan(1.5)
  4. 04theta_B = 56.31°

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