Effects of neighboring transitions on electromagnetically induced absorption and transparency in Rb atoms in circular orthogonal polarization configuration

In this study the effects of neighboring transitions through Doppler broadening on electromagnetically induced absorption and transparency of degenerate two-level system in Rb atoms with respect to circular orthogonal polarization configuration ( s(+) - s(-)) of coupling and probe lasers have been investigated. The dominance of closed F-g = 3 ? F-e = 4 of Rb-85 (F-g = 2 ? F-e = 3 of Rb-87) D2 transition results in the observation of asymmetric and split electromagnetically induced absorptions at all of transitions regardless of the openness or closing of the transitions even in low intensity regime. Slight differences between the spectra of Rb-85 and Rb-87 are analyzed by investigating the variation of the spectra of Rb-85 with an artificial increase of the hyperfine splittings and accordingly with a decreasing of the neighboring effects.