EIT-induced nonlinear precession of the polarization ellipse in rubidium vapor

Summary form only given. In the D/sub 1/ transition in the isotope 87 rubidium atom with no magnetic field present, electromagnetically induced transparency (EIT) can occur due to destructive quantum interference in the lambda transition between the two ground hyperfine states, |F=1, m/sub F/=+1), |F=1, m/sub F/=1), and the single electronically excited hyperfine state |F\´=1, m/sub F/=0), when an elliptically polarized laser beam propagates through a rubidium vapor cell. The stronger circularly polarized /spl sigma//sup +/ component of this light beam, which connects the ground hyperfine state |F=1, m/sub F/=1) to the excited hyperfine state, can be considered as the "coupling" laser, and the weaker circularly polarized /spl sigma/ component, which connects the ground hyperfine state |F=1, m/sub F/=+1) to the excited hyperfine state, can be considered as the "probe" laser. An adiabatic increment in the probe laser intensity (with the coupling laser intensity held fixed) causes an adiabatic population transfer between the two ground hyperfine states. As pointed out by Imamoglu et al., if a fourth nearby level is added to this three-level lambda scheme, two new resonantly-enhanced effects can be produced, i.e., a Kerr effect and a two-photon absorption effect.