Answer to Question #162582 in Optics for Monel

Question

Describe and explain 2 methods for producing plane-polarized light.

Answer 1

Polarization by absorption

Some crystals absorb more light in one incident plane than another, so that light progressing through the material becomes more polarized as they proceed. This anisotropy in absorption is called dichroism. There are several natural and commercial dichroic materials. 

Polarization by scattering

The scattering of light off air molecules produces linearly polarized light in the plane, that is perpendicular to the incident light. The scatterers can be visualized as tiny antennae, that radiate perpendicular to their line of oscillation. If the charges in a molecule are oscillating along the y-axis, they will not radiate along the y-axis. Therefore, at 90° away from the beam direction, the scattered light is linearly polarized. This causes the light to be partially polarized.