Observation of optical Rabi oscillations in transmission signal of atomic vapor under continuous-wave laser excitation

Abstract

We have studied the temporal behavior of the atomic absorption signal under resonant excitation with a continuous-wave laser radiation. Measurements done for D2 line of 85 Rb with ≈ 1 ns temporal resolution have shown irregular oscillatory behavior of the transmission signal, which becomes well pronounced for high laser power, and disappears when the laser is tuned off-resonance. Application of the fast Fourier transform analysis of the transmission signal reveals power-dependent frequency peaks, which are shown to be associated with Rabi frequency. Possible linkage of the observed results with the phase-to-amplitude noise conversion caused by the the phase fluctuations of laser field is discussed.