Electromagnetically induced transparency in an ideal three-level system in 87Rb atoms

We have suggested an ideal three-level system, which is the transition between the magnetic F = 1 and F' = 1 sublevels in the Rb-87 atom, for studying atomic coherence, and we have studied the electromagnetically induced transparency(EIT) in that system. With two counter-rotating circularly polarized lasers, Doppler-free absorption reduction in an ideal R-type three-level atomic system is observed up to 95 %, including optical pumping. After adding an incoherent repumping beam from F = 2 to F = 1 through F' = 2, the maximum absorption reduction is approximately the same as 95 %. In a magnetic field, EIT shows dispersion-like spectrum because of the detuning effect of the coupling laser due to Zeeman splitting of the magnetic sublevels.