Optics Express
Observation of large contrast electromagnetically induced absorption resonance due to population transfer in a three-level Λ-system interacting with three separate electromagnetic fields
Ido Ben-Aroya, G. Eisenstein
Abstract
We describe a new scheme to induce large contrast (nearly 50%) absorption resonances using three co-propagating fields which interact with a three-level Λ-system (obtained by the D(2) transition of (87)Rb atoms) in an N-configuration scheme. A single mode laser which couples the upper ground state to the excited state of (87)Rb is phase modulated at half the hyperfine splitting frequency. The resultant three line spectrum interacts with the atomic vapor yielding a population transfer which increases the absorption by an amount which depends on the carrier to modulation side band intensity ratio.