Question

What is Brewster's law?

Hint:

Brewster's angle is used in polarizing filters to reduce glare. At this angle, light reflected from a surface is completely polarized, which is beneficial in various optical applications.

Answer 1

Brewster's Law:
Brewster's law describes the relationship between the angle of incidence, the refractive indices of the two media, and the polarization of reflected light. Brewster's law states that when unpolarized light strikes a transparent dielectric material at a particular angle, called the Brewster angle, the reflected light is completely polarized. At this angle, the reflected and refracted light are perpendicular to each other. The Brewster angle is given by: \[ \tan \theta_B = \frac{n_2}{n_1}, \] where: - \( \theta_B \) is the Brewster angle (in degrees or radians),
- \( n_1 \) is the refractive index of the medium the light is coming from (e.g., air),
- \( n_2 \) is the refractive index of the medium the light is entering (e.g., glass).
At the Brewster angle, no reflected light is transmitted parallel to the surface, and the reflected light becomes completely polarized. This law is important in the context of optical devices such as polarizing filters.