Bulletin of the Lebedev Physics Institute
Coherent Resonances in a Dipole-Broadened Contour of Selective Reflection from the Transparent Insulator–Atomic Rubidium Vapor Interface
Vladimir A. Sautenkov, Sergey A. Saakyan, Andrey A. Bobrov, E V Vilshanskaya, Boris B. Zelener
Abstract
Abstract Coherent narrow resonances in a homogeneously broadened contour of selective reflection from the interface between a cell window and high-density atomic rubidium vapor, where the dipole broadening greatly exceeds the Doppler width of the unresolved components of rubidium D2 line, are discussed. The formation of coherent resonances is caused by the coherent scattering of probe and pump optical fields from the oscillations of populations of the ground and excited states of atoms at the beat frequency. The width of each resonance depends on the population difference decay rate. Within a simple model conditions are found for observing resonances with a Lorentzian spectral profile. The experimentally recorded coherent resonances are described by a Lorentz function with fitting parameters in the form of amplitude, width, and spectral baseline. In the limit of zero optical saturation the measured half-width of a coherent resonance (HWHM) γres/2π is about 52 MHz, which greatly exceeds the radiative decay rate of the rubidium excited state 5P3/2.