What polarization has a rotating E-field?

The type of polarization that features a rotating electric field (E-field) is known as circular polarization. In circular polarization, the electric field vector rotates in a circular manner as the wave propagates. This rotation can be either clockwise or counterclockwise, leading to what is termed right-hand or left-hand circular polarization.

The choices provided focus on various types of linear and non-linear polarizations. Vertical and horizontal polarizations are specific forms of linear polarization. In these types, the electric field oscillates in fixed vertical or horizontal planes, respectively, rather than rotating. Linear polarization refers to the orientation of the electric field, which does not exhibit any rotational movement of the field vector.

Non-linear polarization often refers to more complex interactions of waves and materials and does not describe a simple rotating E-field like circular polarization does. Therefore, the correct response indicates a concept distinct from those presented in the other choices, emphasizing the specific behavior of circularly polarized waves with a rotating E-field.