My name is Alexander FufaeV and here I write about:
Brewster's Angle: How Light Is Linearly Polarized
Important Formula
$$\class{green}{\varphi_{\text B}} ~=~ \tan \left( \frac{n_2}{\class{blue}{n_1}} \right)^{-1}$$
$$\class{green}{\varphi_{\text B}} ~=~ \tan \left( \frac{n_2}{\class{blue}{n_1}} \right)^{-1}$$
$$\class{blue}{n_1} ~=~ \frac{ n_2 }{ \tan( \class{green}{\varphi_{\text B}} ) }$$
$$n_2 ~=~ \tan( \class{green}{\varphi_{\text B}} ) \, \class{blue}{n_1}$$
What do the formula symbols mean?
Brewster's Angle
$$ \class{green}{\varphi_{\text B}} $$ Unit $$ \mathrm{rad} $$
If the light falls under the Brewster angle \(\varphi_{\text B}\) on the interface of two media (e.g. between air and water), then the reflected beam is linearly polarized.
Refractive index of the first medium
$$ \class{blue}{n_1} $$ Unit $$ - $$
Refractive index of the medium from which the light comes.
Refractive index of the second medium
$$ n_2 $$ Unit $$ - $$
Refractive index of the medium into which the light enters.
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.
$$ \begin{align} \class{green}{\varphi_{\text B}} ~=~ \tan \left( \frac{n_2}{\class{blue}{n_1}} \right)^{-1} \end{align} $$