Electromagnetically induced two-photon transparency in a four level system of rubidium atom

摘要

An experimental study of electromagnetically induced two-photon transparency (EITT) in rubidium atomic vapor at room temperature is presented. A four level system is considered, involving the two-photon absorption process 5S~(1/2) to 8S~(1/2) via an intermediate state 5P~(3/2), and the single-photon control process 5P~(3/2)to 5D~(5/2). A controlling pump laser beam is employed to coherently couple the 5P~(3/2) and 5D~(5/2) states, thus producing two dressed intermediate states, which give rise to destructive interference in the two-photon transition. Fluorescence from 8S~(1/2)to 5P~(1/2) is used to monitor the 5S~(1/2)(F=3) to 8S~(1/2)(F=3) two-photon absorption. An induced two-photon transparency of about 80 percent has been obtained at resonance; the experimental results are in good agreement with the general theory of Agarwal, when the appropriate spectroscopic parameters are employed.