Velocity selective optical pumping effects and electromagnetically induced transparency for D₂transitions in rubidium

Abstract

It is shown that the pump-probe spectroscopy of Λ-type system for the D2 transition of 87Rb exhibits additional absorption enhancement peaks due to velocity selective optical pumping along with the electromagnetically induced transparency (EIT). The separation of these peaks is consistent with the hyperfine splitting of the upper levels. For 85Rb the peaks are not clearly discernible since the hyperfine splitting is much smaller.

Electromagnetically induced transparency in an inhomogeneously broadenedΛtransition with multiple excited levels

“…In a situation for which the Doppler broadening of the medium is larger than the separation between different excited states, these effects are responsible for turning the transparency into absorption for some velocity groups of atoms, which significantly reduces the EIT peak in such system. This reduction is commonly observed in EIT experiments on the D 2 line of alkaline atoms for vapors at room temperature [15,19,32,33]. We show that such effect could cause complete disappearance of the EIT peak, if the atoms with reduced transparency were not optically pumped to levels not participating in the EIT process.…”

Electromagnetically induced transparency in Λ-systems of 87Rb atom in magnetic field

“…In the experiments, the power of the probe beam was fixed at P p = 0.08 mW (Rabi frequency Ω p = 2π [34][35][36]. Among these absorption dips, only dip b exhibits an EIT peak due to the fulfillment of the two-photon resonance condition.…”

Observation of Doppler-free electromagnetically induced transparency in atoms selected optically with specific velocity

“…4. Even though some papers on thermal atoms report the effect of V-type EIT on the saturated spectrum [17], velocity-selective optical pumping effects in -type systems [26], and Doppler-free electromagnetically induced absorption [27], our observation of Doppler-free N-type EIT signals with thermal atoms is a different phenomenon. Figure 4 shows the nonlinear effect of a three-photon process where I b = 35 μW/cm 2 , I p = 6.6 mW/cm 2 or 7.4 mW/cm 2 , and I c = 135 mW/cm 2 .…”