Waves vibrating perpendicular to this direction are absorbed by it. Two polarizing filters aligned in the same direction allow polarized light to pass through. The first filter is called the polarizer and the second is called the analyzer. It can be demonstrated that light can be naturally polarized simply by observing light reflected from a surface. The reason for the polarization lies in the fact that the light waves are absorbed and re-emitted when they are reflected.
Large reflection occurs if the polarization is in the plane of the surface.
This is because the electrons, which absorb and re-emit radiation, vibrate more easily in the plane of the surface than perpendicular to it. At normal incidence all directions of polarization are equally reflected. To verify this, look at the glare caused by reflected light off the top of a desk or the floor, and then view the glare through a single polarizing sheet. As you rotate the polarizer much of the glare will disappear and reappear. When the glare is minimized, the polarization direction of the polarizing film is vertical.