Standing wave pump field induced coherent non-linear resonances in rubidium vapor

Abstract A variety of coherent non-linear resonances are investigated experimentally in the presence of a standing wave pump field for the D 2 transition of both Rb isotopes. Under Λ configuration, the observed enhanced absorption dips along with electromagnetically induced transparency (EIT) peak are described. The effect of the pump frequency detuning on EIT is studied. At exact resonance, the EIT splitting with FWHM of 2.0 and 1.2 MHz is attributed to the spatial modulation of EIT resonance in the standing wave field. In a V configuration, velocity selective resonances (VSR) together with electromagnetically induced absorption (EIA) dip are observed and studied at different pump–probe intensity ratios.