Polarization spectroscopy
Polarization spectroscopy comprises a set of spectroscopic techniques based on polarization properties of light. By analyzing the polarization properties of light, decisions can be made about the media that emitted the light. Alternatively, a source of polarized light may be used to probe a media; in this case, the changes in the light polarization allow to infer the media properties.
In general, any kind of anisotropy in the media results in some sort of change in polarization. Such an anisotropy can be either inherent to the media, or imposed externally.
