Photon Spectrum in Laser-Induced Autoionization

Abstract
A quantum electrodynamic treatment of an autoionizing atom excited by a laser field is presented. As the main result, the authors present the average number of photons emitted into a particular mode of the electromagnetic field. In the case of a symmetric autoionizing resonance, the spectrum presented here resembles the power spectrum in resonance fluorescence of a two-level atom. For an asymmetric resonance, however, this spectrum manifests the confluence of coherences. The total number of scattered photons has a maximum at the confluence intensity. The spectrum is asymmetric in this case.