Verdet constant

The Verdet constant is a material property that indicates the strength of the Faraday effect for a given substance. Its value depends on the wavelength of light. The Verdet constant is named after the French physicist Marcel Émile Verdet ( 1824-1866 ). In the International System of Units it has the unit RADM -1T -1. By convention, there is a positive Verdet constant for a substance which, counterclockwise rotation acts on light propagating parallel to the magnetic field lines.

The angle through which the polarization is rotated as it passes through a material with thickness through the Faraday effect is proportional to the Verdet constant:

The magnetic flux density in the material, parallel to the propagation direction of light.

The value of the Verdet constant can be calculated from the dispersion of the material under consideration:

Here is the wavelength of the light, the velocity of light, the elementary charge and the mass of the electron.