Polarization
In an ordinary light, the vibration is in all directions perpendicular to its direction of propagation. It can be resolved into two perpendicular vibrating components. When a polarizing filter is put in the middle of a beam of ordinary light, only those waves vibrating in one plane can pass through and others will be blocked. A polarized light with half its original intensity is then produced.

Polarization by Reflection

Between two transparent media the

reflected light is partially polarized.

If the reflected and refracted rays are

perpendicular, the reflected light is

completely polarized.