Brewster's Angle: How Light Is Linearly Polarized

When unpolarized light falls on the interface of two dielectric media (e.g., air and glass) with refractive indices \(n_1\) and \(n_2\) at the Brewster angle (\(\varphi_{\text B}\)), the reflected light becomes fully linearly polarized, specifically perpendicular to the plane of incidence (s-polarization). In contrast, the transmitted light is only partially linearly polarized.