Effects of vector magnetic field on electromagnetically induced transparency with lin ⊥ lin polarization

The effect of a vector magnetic field was studied on electromagnetically induced transparency (EIT) with linear ⊥ linear polarization of the probe and pump beams in 87Rb−D2 transition with a vapor cell at room temperature. The dependence of EIT on the direction of the quantization axis and the relative orientation of the polarizations of the applied electric fields was studied experimentally. We show that from the relative strengths of σ and π EITs, the direction of the magnetic field can be found. Moreover, from the relative separation between σ and π EITs, the strength of the magnetic field can be calculated. We also demonstrate that the EIT peak amplitudes show oscillatory behavior depending upon the orientation of the laser polarization relative to the magnetic field direction. To understand the experimental observations, a theoretical study was done numerically considering all 13 Zeeman sub-levels. Apart from the numerical simulation, a toy model was also constructed to obtain an analytical response of the medium considering the velocity distribution. The dependencies of the magnetic field direction and polarization direction of the electric field were explicitly derived with the analytical model.