Fresnel–Arago Laws

Sir George Gabriel Stokes (1819 - 1903) was led to his formulation of Stokes Polarization Parameters in order to provide a suitable mathematical description of the Fresnal-Arago laws.

Fresnel–Arago Laws (1811) are based on experiments carried out with an unpolarized light source. The original laws were stated as:

1. Two rays of light polarized in the same plane interfere in the same manner as ordinary light
2. Two rays at right angles do not interfere
3. Two rays polarized at right angles from ordinary light and brought into the same plane of polarization do not interfere in the ordinary sense
4. Two rays polarized at right angles interfere when brought into into the same plane of polarization

They are stated clearer below.

1. Two orthogonal, coherent linearly polarized waves cannot interfere.
2. Two parallel coherent linearly polarized waves will interfere in the same way as natural light.
3. The two constituent orthogonal linearly polarized states of natural light cannot interfere to form a readily observable interference pattern, even if rotated into alignment (because they are incoherent).

ARAGO, Dominque Francois Jean, 1786-1853, French physicist

FRESNEL, Augustin Jean, 1788-1827, French physicist