Revisiting photon-statistics effects on multiphoton ionization

Abstract

In this paper, we extend the results of an earlier paper in which we had demonstrated the limitations of the notion of nonresonant multiphoton ionization, in the exploration of photon statistics effects in non-linear processes. Through the quantitative analysis of specific realistic processes, we provide the connection to conditions of intensity and pulse duration necessary in relevant experiments, including a recent seminal experiment demonstrating the effect of superbunching found in squeezed radiation.

Fluorescence polarization as a precise tool for understanding nonsequential many-photon ionization

“…More recent experiments do report a total ionization cross section which is extracted from measurements of ion or fluorescence yields, however, more often than not, the corresponding uncertainty cannot be estimated. While some of these experimental cross sections seem to be in agreement with theory [3][4][5][6] within an order of magnitude [7,8], other [9,10] report values of even two or three orders of magnitude larger than theoretically calculated predictions. There are few measurements which were reported with the experimental uncertainties [11][12][13], however, since second-order processes depend quadratically on the incoming beam intensity, the uncertainties in measured cross sections are strongly affected by beam parameters which determine the absolute intensity.…”

Squeezed Coherent States in Double Optical Resonance

“…The simplest example illustrating this dependence is the transition from a bound state to a continuum via the absorption of N photons, i.e., N-photon ionization. The derivation of the transition probability per unit time for N-photon ionization when all real bound atomic intermediate states are assumed sufficiently far from resonance [31][32][33][34] indicates that the rate of the process is proportional to an effective N-photon matrix element multiplied by the Nth-order intensity correlation function [15,16]. In view of the dependence of the correlation functions on the stochastic properties of the radiation, the rate of such a process can be affected dramatically by the intensity fluctuations of the source [35].…”