Light Beating Spectroscopy

Gareth Parry

H. Z. Cummins, Edward R. Pike

H. Z. Cummins, Edward R. Pike

Yukio Fukuda, Tuneo HASHI

DONG TAI-QIAN, Harold J. Metcalf

In ordinary quantum-beat spectroscopy the excitation mechanism (e.g., laser pulse) is not expected to affect the results because the measurements are made on a freely evolving atom in the dark (after pulse ends). In this paper we point out an example where this is not so. As an example, we show how light shifts can alter the results of time-delayed measurements.

M. S. Slutsky, Robert R. Lewis

The theory of the Forrester effect is reexamined in both classical and quantum terms. We show that temporal coherence (light beating) can arise from the interference of fields produced either by single atoms or by pairs of atoms. The singles terms, which dominate for a collisionless source with low intensity, give a light-beating signal-to-noise ratio of order unity, independent of the intensity and wavelength. This signal is also unaffected by Doppler broadening. The doubles terms, originally analyzed by Forrester, give a signal-to-noise ratio proportional to the intensity and to the square of the wavelength, and subject to Doppler broadening. Our results suggest the possibility of a new type of rf and microwave spectroscopy for excited atoms.