Observation of Faraday Rotation in Cold Atoms in an Integrating Sphere

Ben-Chang Zheng, Hua-Dong Cheng, Yan-Ling Meng +3 more

The Faraday rotation of weak linearly polarized probe light is observed as it passes through a sample of cold 87 Rb atoms prepared by diffused light in an integrating sphere. The rotation angle of the probe light-polarization as functions of laser intensity, detuning and biased magnetic field is measured. A Ramsey fringe with a linewidth of 35 Hz and contrast up to 92% is demonstrated. This method has potential applications in improving the performance of atomic clocks with cold atoms.

А. А. Папченко, Evgenii A. Yukov

Jinyin Wan, Yanling Meng, Ling Xiao +5 more

We present a modified scheme for detection of the magneto-optical rotation (MOR) effect, where a linearly polarized laser field is interacting with cold $^{87}$Rb atoms in an integrating sphere. The rotation angle of the probe beam's polarization plane is detected in the experiment. The results indicate that the biased magnetic field, the probe light intensity and detuning, and the cold atoms' temperature are key parameters for the MOR effect. This scheme may improve the contrast of the rotation signal and provide an useful approach for high contrast cold atom clocks and magnetometers.

Lauro Tomio, A. Gammal, F. Kh. Abdullaev

D.P. Bhattacharya, Z. S. Kachlishvili

Adam M. Wojciechowski, Eric Corsini, Jerzy Zachorowski +1 more

We report on the first observation of Nonlinear Faraday Rotation (NFR) with cold atoms prepared in a magneto-optical trap (MOT) at ∼100µK temperature. The nonlinearity of rotation results from long-lived coherence of ground-state Zeeman sublevels [1], which makes NFR a candidate for the study and sensitive detection of qubits.