Two kinds of high-contrast optical filters for the detection of Stokes and anti-Stokes photons from cesium ensemble

摘要

We report experimental investigations of two kinds of high-contrast optical filters by utilizing a laser-pumped atomic vapor and properly-designed Fabry-Perot bulk etalon, which are based on the demand of the detection of quantum correlated Stokes and anti-Stokes photon pairs in a Λ-type three-level atomic ensemble, respectively. Laser-pumped cesium (Cs) atomic filter achieves typical peak transmission ~ 74.3% and the distinction ratio between excitation channel and 9.19GHz- frequency-detuned signal channel is ~ 26.7 dB at 47.15°C. The transmission peak can be tuned within the range of Doppler line-width of Cs D_2 line. The temperature-stabilized narrow-band etalon filter with dozens of GHz resonant transmission tunability is realized with typical peak transmission of ~ 91.7% and the distinction ratio between pump and signal channel of ~27.5 dB. These techniques are useful for atom-photon interaction experiments, especially for Stokes and anti-Stokes photon pairs generation experiments based on collective Raman excitation of Cs atomic ensemble.