Rotating Polarization-Induced Resonance in Atoms and Molecules

The existence of a novel resonance in the modulation of the fluorescence light emitted by an atom or a molecule when coherently excited by a rapidly rotating linearly polarized light beam is predicted. Such resonances are experimentally observed due to a transfer of coherence from light to atoms or molecules, via either stimulated emission or absorption of light, without having to shift the positions of the levels by an external perturbation. These resonances directly permit the measurement of energy level lifetimes, even in the case where usual magnetic resonance methods would require the use of large magnetic fields.