Line shapes in polarization spectroscopy for the rubidium D1 line in an external magnetic field

We present a theoretical and experimental study of line shapes in polarization spectroscopy for the D1 transition line of 85Rb atoms in the presence (or absence) of a constant magnetic field. After the effect of the pump beam is calculated using rate equations (while the probe beam is neglected) the induced circular anisotropy is calculated by averaging the susceptibility over a Maxwell–Boltzmann velocity distribution and various atomic transit times. We find that the calculated results either in the absence or presence of an external magnetic field are in good agreement with experimental results.