Accurate [Formula Presented] polarimetry using the Rb Zeeman frequency shift due to the [Formula Presented] spin-exchange collisions

We describe a method of [Formula Presented] polarimetry relying on the polarization-dependent frequency shift of the Rb Zeeman resonance. Our method is ideally suited for on-line measurements of the [Formula Presented] polarization produced by spin-exchange optical pumping. To calibrate the frequency shift we performed an accurate measurement of the imaginary part of the [Formula Presented] spin-exchange cross section in the temperature range typical for spin-exchange optical pumping of [Formula Presented] We also present a detailed study of possible systematic errors in the frequency shift polarimetry.