It is shown that, as a result of recoil during spontaneous emission, optical activity in a vapor can be induced under the action of resonant pump and probe fields. For field geometries that exclude other mechanisms for rotation of the probe field's plane of polarization, the recoil accompanying spontaneous emission provides the needed coupling between the spatial and internal atomic degrees of freedom to produce an optically active medium. A transition between ground and excited states, each having angular momentum $J=\frac{1}{2}$ , is analyzed in detail. The effect can be interpreted as the result of pump field scattering off a spatial polarization grating of ground-state Zeeman coherence.It is shown that, as a result of recoil during spontaneous emission, optical activity in a vapor can be induced under the action of resonant pump and probe fields. For field geometries that exclude other mechanisms for rotation of the probe field's plane of polarization, the recoil accompanying spontaneous emission provides the needed coupling between the spatial and internal atomic degrees of freedom to produce an optically active medium. A transition between ground and excited states, each having angular momentum $J=\frac{1}{2}$, is analyzed in detail. The effect can be interpreted as the result of pump field scattering off a spatial polarization grating of ground-state Zeeman coherence.

Physical Review AOct 1, 199510 citations

Nonlinear Faraday rotation in electromagnetically induce transparency medium

She Yan-Chao, Weixi Zhang, Denglong Wang

By using multiple-scale methods, we study analytically the propagation properties of the weak linear polarization probe optical field in a cold lifetime-broadened five-level V type atomic system via electromagnetically induced transparency. It is shown that with the strength of the coupling field increasing, the absorption of the probe optical field decreases rapidly and the group velocity of the probe optical field increases quickly under the consideration of linear effect. However, the velocity is several orders of magnitude slower than the light speed in vacuum. Meanwhile, we find that for the same magnetic field the nonlinear Faraday rotation direction is opposite to linear Faraday rotation, and its rotation angle grows bigger than that of linear Faraday rotation. These results mean that the Faraday rotation of the electromagnetically induced transparency medium can be controlled by the nonlinear effect.By using multiple-scale methods, we study analytically the propagation properties of the weak linear polarization probe optical field in a cold lifetime-broadened five-level V type atomic system via electromagnetically induced transparency. It is shown that with the strength of the coupling field increasing, the absorption of the probe optical field decreases rapidly and the group velocity of the probe optical field increases quickly under the consideration of linear effect. However, the velocity is several orders of magnitude slower than the light speed in vacuum. Meanwhile, we find that for the same magnetic field the nonlinear Faraday rotation direction is opposite to linear Faraday rotation, and its rotation angle grows bigger than that of linear Faraday rotation. These results mean that the Faraday rotation of the electromagnetically induced transparency medium can be controlled by the nonlinear effect.

Acta Physica SinicaJan 1, 20114 citations

J=\frac{1}{2}

, is analyzed in detail. The effect can be interpreted as the result of pump field scattering off a spatial polarization grating of ground-state Zeeman coherence.