Sub-Doppler DAVLL spectra of the D1 line of rubidium: a theoretical and experimental study

We present a comprehensive theoretical and experimental study of the lineshape in sub-Doppler dichroic atomic vapor laser lock (DAVLL) spectroscopy of the D1 transition lines of 87Rb and 85Rb atoms. By calculating sub-Doppler DAVLL spectra with both density matrix equations and rate equations, we found that the coherence effect is significantly dependent on the branching ratios of the transition lines. In addition, we investigated the dependence of the amplitude and slope of the spectra on the applied magnetic field and pump beam power, and found good agreement with the results calculated from the rate equations.