Why faraday rotation is not effective in case of circular polariation?

As in case of linear polarization the plane of polarization gets rotated. Why it's not happening with circular polarization?

• What is the plane of polarization for a circularly polarized beam? If the plane were rotated, how would you know? Dec 7, 2016 at 18:20
• @JonCuster Do you mean that the plane gets rotated but it does not have any impact? Dec 7, 2016 at 21:57

The Faraday effect is the rotation of the polarization plane (proportional to the length $l$ and magnetic field $B$ of linearly polarized light when propagating along a magnetic field $B$ applied to a (transparent) material. Linearly polarized light can be decomposed into left and right circularly polarized light. The rotation of the linear polarization direction is due to a difference in the refractive index for right and left circularly polarized light induced by the magnetic field leading to a phase difference proportional to $l$ and $B$, which explains the rotation of the linear polarization. Thus the influence of $B$ on the phase velocity of left and right circularly polarized light is essential to explain the Faraday effect .