Stokes parameters

Of elliptically polarized incident radiation, these are given by
s 0 0 = E 1 0 + E 2 0
s 1 0 = E 1 0 − E 2 0
s 2 0 = 2 E 1 0 E 2 0 cos ⁡ δ 0
s 3 0 = 2 E 1 0 E 2 0 sin ⁡ δ 0
where E 1 0 and E 2 0 specify the irradiances of the incident light polarized with their electric vectors vibrating perpendicular and parallel to the scattering, respectively and δ 0 is the phase difference between these electric vectors.
See also: scattering matrix
Source:
PAC, 1983, 55, 931 (Definitions, terminology and symbols in colloid and surface chemistry. Part 1.14: Light scattering (Provisional)) on page 933