Polarizer

Synonyms

Polarization filter; Polarizing film

Related Concepts

Polarization

Definition

The device which polarizes the light when the light goes through it.

Background

Polarizers makes the light oscillate in one direction. The polarization state of light changes if it hits any materials, and polarization of the light is useful in many application fields. Polarizers are made artificially since natural objects usually do not change the light to be always perfectly polarized.

Theory

There are two kinds of perfectly polarized light: linearly polarized light and circularly polarized light. This entry first explains linear polarizers, and then explains circular polarizers.

Figure 1 is the typical illustration of linear polarizer. Linear polarizer is often expressed as a circle with some straight lines inside. The orientation of the lines expresses the orientation of oscillation of the light transmitted through the polarizer. Figure 1represents the case when the unpolarized light goes...