Polarization spectroscopy of the ^1S_0-^3P_1 transition of mercury isotopes at 253.7??nm

We experimentally observe polarization spectroscopy (PS) of the S_01-P3_1 transition of mercury atom gases at 253.7 nm. The PS signal can be observed in all six richly abundant isotopes and the PS signal of six transitions for laser cooling are all clear and of a dispersive line shape. The optimized pump power and probe power are found for the PS of Hg202. We find the linearly polarized component in the pump beam will distort the original PS signal due to the use of linear PS. Consequently, the purity of the pump beam is crucial to laser frequency stabilization by PS.