The operation of polarimetric based single beam three axis atomic magnetometer is studied. The magnetometer operates in presence of small bias magnetic field. Its salient features are compared with the analysis of Bloch equation. The sensitivity of the device along three orthogonal directions are measured in low frequency regime, where 1/f noise adversely affect the sensitivity. The crosstalk among the three axes magnetic field measurements and relative phase shifts are analysed using Lissajous plot. The sensitivity of the magnetometer is found to be < 20 pT Hz^−1/2@400 mHz in any direction. The investigated magnetometer is suitable for space application, where overall size of the device is of prime importance.