POLARIZATION

Of an electromagnetic wave , the property that describes the orientation, i.e., time -varying direction and amplitude, of the electric field vector. ( 188 ) Note 1: States of polarization are described in terms of the figures traced as a function of time by the projection of the extremity of a representation of the electric vector onto a fixed plane in space, which plane is perpendicular to the direction of propagation . In general, the figure, i.e., polarization, is elliptical and is traced in a clockwise or counterclockwise sense, as viewed in the direction of propagation. If the major and minor axes of the ellipse are equal, the polarization is said to be circular . If the minor axis of the ellipse is zero, the polarization is said to be linear . Rotation of the electric vector in a clockwise sense is designated right-hand polarization , and rotation in a counterclockwise sense is designated left-hand polarization . Note 2: Mathematically, an elliptically polarized wave may be described as the vector sum of two waves of equal wavelength but unequal amplitude, and in quadrature (having their respective electric vectors at right angles and /2 radians out of phase ).