Polarimetria
Polarimetria, or polarimetry, is the measurement and interpretation of the polarization state of light or other electromagnetic radiation. The primary goal is to determine how the polarization is affected by a sample, which can reveal properties of the light source, the sample's optical activity, or its microstructure. In its classical form, polarimetry assesses the rotation of the plane of linearly polarized light caused by chiral or optically active substances, described by the specific rotation alpha in a given concentration and path length. In modern practice, polarimetry is often framed in the Stokes–Mueller formalism, where the polarization state is represented by Stokes parameters and a sample is described by a Mueller matrix that transforms the input state to the output state.
Instrumentation typically includes a light source, a polarizer to define the input polarization, a sample holder,
Applications span chemistry, biology, materials science, and astronomy. Optical rotation measurements are used to determine concentration
Historically, polarimetry traces to the work of Jean-Baptiste Biot in the early 19th century, who documented