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

TL;DR

This study observes optical Rabi oscillations in the transmission signal of rubidium vapor under continuous-wave laser excitation, revealing power-dependent oscillatory behavior linked to Rabi frequency and phase noise effects.

Contribution

It provides experimental evidence of optical Rabi oscillations in atomic vapor with high temporal resolution and analyzes their dependence on laser power and resonance conditions.

Findings

Oscillatory transmission signals become prominent at high laser power.

Oscillation frequencies correlate with Rabi frequency and laser power.

Oscillations disappear off-resonance, confirming their link to atomic 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 85Rb 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.