In college physics "Optics", you will be exposed to this knowledge in detail. As you know, light has electric and magnetic components. Let me briefly talk about how reflected light is polarized.

According to Fresnel formula, e'/e = tan (θ-θ')/tan (θ+θ''), where e' is the electric field component of reflected light, θ is the incident angle and θ'' is the refraction angle. The so-called Brewster angle is θ+θ″= 90 degrees. It can be seen that E'/E=0 at this time, that is, e' is zero, which means that the electric field component of the reflected light is zero, only the magnetic field component, that is, the reflected light becomes linearly polarized light at this time.

So is the magnetic field component of refracted light.

I hope I can help you, O(∩_∩)O~