Two-Level Atoms in an Intense Monochromatic Field: A Review of Recent Experimental Investigations
The effect of an intense monochromatic field on the behavior of a two-level atom with natural damping has recently been studied experimentally using stable tunable lasers and atomic beams. A number of researchers have measured the spectrum of the emission, and more recently, the absorption of the strongly driven atoms for both on-resonance and off-resonance excitation. In addition, the energy levels of the atoms have been carefully probed to examine in some detail, the ac Stark effect induced by a strong resonant and nearly resonant field. The paper will cover a brief review of the measurements that have been performed so far by the various groups, a comparison of the experimental results with theoretical predictions, as well as a discussion of the experimental problems in performing such measurements.