Axis x and y are the initial, unrotated axes, ξ and η are a new set of axes along the rotated. 2. The area of polarization ellipse depends on the lengths of major and minor axes, amplitudes E 0x and E 0y and phase shift ϕ. 3. The angle β p =arctg(E 0y /E 0x) is called the auxiliary angle (0≤ψ≤π/2). 4. The rotation angle ψ (-β p ≤ψ≤β p) is the angle between axis x and major axis ξ. This angle is called the azimuth angle. 5. The ellipticity is the major axis to minor axis ratio (b/a).