Electromagnetically induced transparency of laser-cooled rubidium atoms in three-level Lambda-type systems

S. A. Hopkins, Eric W. Usadi, H.X. Chen +1 more

Min Yan, Edward G. Rickey, Yifu Zhu

We report experimental studies of electromagnetically induced transparency in Λ-type and ladder-type atomic systems realized in 87Rb atoms cooled and confined in a magneto-optical trap. Complete transparency is observed in the Λ-type system with a moderate coupling field. Comparison between the two systems reveals that at the line center of a weak probe transition, destructive interference occurs for the Λ-type system, whereas constructive interference occurs for the ladder-type system. We discuss conditions of complete transparency in the Λ-type system that contains hyperfine magnetic sublevels. Our experimental measurements for the two systems agree with theoretical calculations based on simple three-level Λ-type and ladder-type models.

Josh W. Dunn, Flávio C. Cruz, Jan W. Thomsen +1 more

Yongqing Li, Min Xiao

Yongqing Li, Min Xiao

An electromagnetically induced transparency is observed at one arm of a three-level \ensuremath{\Lambda}-type system in a rubidium D1 line (794.8 nm) with an 85% reduction in absorption, when a pumping field is present at the other arm. This reduction in absorption for the weak probe field is due to the atomic coherence produced by the strong pumping field. This experiment is done in a Rb vapor cell at room temperature with cw diode lasers for both pumping and probe beams in a Doppler-free configuration. A simple theoretical treatment including Doppler broadening is in good qualitative agreement with the experimental measurement.

Mina Parvaz, Hassan Randjbar Askari, Hamid Reza Baghshahi