Light and Color - Mission LC2 Detailed Help

Unpolarized light is approaching a Polaroid filter whose transmission axis is aligned vertically. Upon passing through the filter, the light will have ____ and be vibrating in a ____ plane of vibration.


Polarization by Transmission Through a Filter:
A Polaroid filter is a device that polarizes light. The filter serves to filter out one-half of the vibrations of unpolarized light as the light passes through the filter. Unpolarized light enters the Polaroid filter and polarized light exits the filter with one-half the original intensity and with vibrations in a single plane. The unpolarized light becomes polarized.

Polaroid Filter and the Transmission Axis:
A Polaroid filter is said to have a transmission axis. The filter can be thought of as having long-chain molecules that are aligned within the filter in the same direction. Unpolarized light can be thought of as consisting of waves with electric and magnetic components of vibration that are directed in a multitude of planes. The electric and magnetic components that are aligned in the direction of the molecules become absorbed by the molecules. Those components that are perpendicular to the molecules emerge from the filter. Thus, the transmission axis is aligned perpendicular to the molecules of the filter. One-half of the original vibrations emerge from the filter. The emerging vibrations are aligned in a direction perpendicular to the molecules and parallel to the transmission axis.