Polarization

Polarization is a term used in physics to describe the orientation of oscillations in a transverse wave, as well as in social science to denote division into opposing groups. In optics, polarization most often refers to the orientation of the electric field in light, which can be linear, circular, or elliptical.

In optical systems, polarization can be manipulated by filters, wave plates, and reflective interfaces. A linear polarizer transmits only components of the electric field along a given direction. Reflections at certain angles, such as Brewster's angle, partially polarize light. Scattering and diffraction can also alter polarization.

Mathematically, polarized light can be described with Jones calculus for fully polarized waves and with Stokes parameters for partially polarized or incoherent light. The polarization state traces an ellipse called the polarization ellipse, and the set of all states can be represented on the Poincaré sphere.

Applications include fiber-optic communications, where matching polarization improves signal quality; antennas with defined polarization; liquid crystal displays and 3D cinema; and polarization-sensitive remote sensing.

In social science, polarization describes the divergence of opinions into two or more groups with little middle ground. It is measured by shifts in attitudes, increased homogeneity within groups, and greater ideological distance between groups. Causes include selective exposure, media fragmentation, and social network effects. Mitigation approaches emphasize dialogue, inclusive institutions, and policies that reduce perceived zero-sum competition.