How Polarized Light Working
When light is incident obliquely on a glass surface, its reflectivity changes with the polarization direction of the incident light. Light waves vibrating in the plane formed by the normal to the glass surface and the incident light beam are called P polarized light, and light waves vibrating in the direction orthogonal to the P polarized light are called S polarized light. The polarization states in other directions can be considered as the result of the synthesis of P polarization and S polarization in different proportions.
The reflectivity of P polarization and S polarization is determined by the incident angle and the refractive index of the glass. Because they follow different laws, the reflectivity of P polarization and S polarization is also different.
