Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Photoelectron spectrum from laser-induced autoionization in the presence of spontaneous emission and off-diagonal relaxation

G. S. Agarwal, Dan Agassi

Published Apr 1, 1983• 28 citations
Publisher

Abstract

The exact solution of the Fano model, including both radiative recombination to the initial state (recycling) and off-diagonal phase-jitter relaxation, is obtained by two different methods. We derive a simple substitution rule stating that, by replacing $\ifmmode\pm\else\textpm\fi{}i{\ensuremath{\omega}}_{L}\ensuremath{\rightarrow}\ifmmode\pm\else\textpm\fi{}i{\ensuremath{\omega}}_{L}+{\ensuremath{\gamma}}_{T}$, the phase-jitter effects are included. The time dependence of the solution has a convolution form. The results for the electron spectrum exhibit an increasing elastic-peak line narrowing the faster the spontaneous decay becomes. For very fast spontaneous decay, the elastic linewidth saturates to ${\ensuremath{\gamma}}_{T}$. The relevant thresholds are discussed and demonstrated.

DOI
10.1103/physreva.27.2254

Related papers

Line narrowing and photoelectron trapping in multiphoton ionization spectroscopy

Zhifang Deng

We study a theoretical model of photoionization. An initially occupied ground electronic state is ionized to a flat continuum by two-photon excitation. There are two near-resonant intermediate excitation states. The line-narrowing confluence effect and population trapping are studied. We show that we cannot define an effective Hamiltonian to relate our model to the Fano model. In connection with recent studies of laser-induced autoionization (LIA), we show several differences between our model and LIA. For example, we show that the zero in the absorption spectrum and in the photoelectron spectrum has different features compared with that in the Fano model [ Phys. Rev.124, 1866 ( 1961)]. We also show that a laser-power-independent confluence condition and a complete population-trapping condition can be found in our model.

Journal of the Optical Society of America B•Dec 1, 1984•12 citations

Restoring dark lines in spontaneous emission via Fano interference

Emmanuel Paspalakis, P. L. Knight

We investigate the effects of spontaneous emission on two different laser-driven autoionization systems. We find that, under specific conditions, the relaxation decay processes can interfere destructively and lead to dark lines and spectral narrowing in the spontaneous emission spectra of these systems.

Journal of Modern Optics•Mar 1, 1999•6 citations

Dressed-resonance representation for strong photoexcitation of continuum states with application to laser-enhanced autoionization

Dan Agassi, Joseph H. Eberly

We introduce in the context of a simple soluble model for laser-enhanced autoionization a new representation---the dressed-resonance representation (DRR). The model includes one autoionizing state, one flat electron continuum, one continuous driving laser of arbitrary strength, and two types of relaxations, i.e., spontaneous decay of the continuum and autoionizing state back to the initial state (spontaneous recycling) and phase-jitter noise in the driving laser. The DRR is a natural extension of the dressed-states representation, employed in strong-field discrete-discrete transitions, to discrete-continuum transitions. We focus on two observables, i.e., the temporal initial state population and the photoelectron spectrum. The emphasis is on strong-field effects. The DRR yields simple, transparent, analytical expressions for the above observables in the no-relaxations limit of the model. These results are complemented by a systematic analysis of the exact solution in all qualitatively distinct physical regimes.

Physical Review A•Oct 1, 1986•12 citations

Photoemission spectra from autoionizing states under recycling conditions

G. S. Agarwal, Stanley L. Haan, J. Cooper

Spectral features of the radiation emitted by autoionizing states in the presence of a strong laser field are calculated under the condition of multiple photon absorption and emissions. The method is based on the exact solution of the master equation for the recycled system. The decay spectra are found to exhibit sharp maxima at the laser frequency and, for large values of the Fano $q$ value, sidebands which are reminiscent of the triplet which one finds in the context of a two-level atom.

Physical Review A•Aug 1, 1983•20 citations

Laser-induced autoionization in the presence of radiative damping and transverse relaxation

Joseph W. Haus, Maciej Lewenstein, Kazimierz Rza̧żewski

A model for laser-induced autoionization is considered which includes two qualitatively different relaxation mechanisms: radiation damping to the ground state and phase fluctuations. Analytic solutions are presented for the first- and second-moment correlation functions of the atomic and photon operators in the Heisenberg picture. We present an explicit analysis of the spectrum of emitted photons at long times and investigate the effect of both relaxation mechanisms, as well as the influence of detuning and laser intensity, on this photoemission spectrum.

Physical Review A•Oct 1, 1983•31 citations

Radiative decay of autoionizing states in laser fields. I. General theory

G. S. Agarwal, Stanley L. Haan, J. Cooper

A theory describing the radiative decay of an autoionizing state under strong pumping by a coherent field is developed. The theory systematically takes into account the radiative decay of the unperturbed continuum. The problem at hand corresponds to the case of strongly coupled bound states decaying to electron and photon continua with the two continua also weakly coupled to each other. A master equation describing the time evolution of the atomic system is derived, and its exact solution under arbitrary initial conditions is given. The effect of radiative decay on the Fano profiles and photoelectron spectra is analyzed in detail. The time development of the system is also examined. The radiative decay of the autoionizing state and the unperturbed continuum changes the spectra in a significant way. The characteristics of the spectra are correlated with the dressed states (with complex energies) of the system. The changes in the structure of the dressed states as a function of the system parameters such as the spontaneous-emission rate and laser intensity are discussed in detail.

Physical Review A•May 1, 1984•77 citations
The exact solution of the Fano model, including both radiative recombination to the initial state (recycling) and off-diagonal phase-jitter relaxation, is obtained by two different methods. We derive a simple substitution rule stating that, by replacing \ifmmode±\else\textpm\fii\ensuremathωL\ensuremath→\ifmmode±\else\textpm\fii\ensuremathωL+\ensuremathγT\ifmmode\pm\else\textpm\fi{}i{\ensuremath{\omega}}_{L}\ensuremath{\rightarrow}\ifmmode\pm\else\textpm\fi{}i{\ensuremath{\omega}}_{L}+{\ensuremath{\gamma}}_{T}\ifmmode±\else\textpm\fii\ensuremathωL​\ensuremath→\ifmmode±\else\textpm\fii\ensuremathωL​+\ensuremathγT​, the phase-jitter effects are included. The time dependence of the solution has a convolution form. The results for the electron spectrum exhibit an increasing elastic-peak line narrowing the faster the spontaneous decay becomes. For very fast spontaneous decay, the elastic linewidth saturates to \ensuremathγT{\ensuremath{\gamma}}_{T}\ensuremathγT​. The relevant thresholds are discussed and demonstrated.
We study a theoretical model of photoionization. An initially occupied ground electronic state is ionized to a flat continuum by two-photon excitation. There are two near-resonant intermediate excitation states. The line-narrowing confluence effect and population trapping are studied. We show that we cannot define an effective Hamiltonian to relate our model to the Fano model. In connection with recent studies of laser-induced autoionization (LIA), we show several differences between our model and LIA. For example, we show that the zero in the absorption spectrum and in the photoelectron spectrum has different features compared with that in the Fano model [ Phys. Rev.124, 1866 ( 1961)]. We also show that a laser-power-independent confluence condition and a complete population-trapping condition can be found in our model.
We introduce in the context of a simple soluble model for laser-enhanced autoionization a new representation---the dressed-resonance representation (DRR). The model includes one autoionizing state, one flat electron continuum, one continuous driving laser of arbitrary strength, and two types of relaxations, i.e., spontaneous decay of the continuum and autoionizing state back to the initial state (spontaneous recycling) and phase-jitter noise in the driving laser. The DRR is a natural extension of the dressed-states representation, employed in strong-field discrete-discrete transitions, to discrete-continuum transitions. We focus on two observables, i.e., the temporal initial state population and the photoelectron spectrum. The emphasis is on strong-field effects. The DRR yields simple, transparent, analytical expressions for the above observables in the no-relaxations limit of the model. These results are complemented by a systematic analysis of the exact solution in all qualitatively distinct physical regimes.
Spectral features of the radiation emitted by autoionizing states in the presence of a strong laser field are calculated under the condition of multiple photon absorption and emissions. The method is based on the exact solution of the master equation for the recycled system. The decay spectra are found to exhibit sharp maxima at the laser frequency and, for large values of the Fano qqq value, sidebands which are reminiscent of the triplet which one finds in the context of a two-level atom.
A model for laser-induced autoionization is considered which includes two qualitatively different relaxation mechanisms: radiation damping to the ground state and phase fluctuations. Analytic solutions are presented for the first- and second-moment correlation functions of the atomic and photon operators in the Heisenberg picture. We present an explicit analysis of the spectrum of emitted photons at long times and investigate the effect of both relaxation mechanisms, as well as the influence of detuning and laser intensity, on this photoemission spectrum.
A theory describing the radiative decay of an autoionizing state under strong pumping by a coherent field is developed. The theory systematically takes into account the radiative decay of the unperturbed continuum. The problem at hand corresponds to the case of strongly coupled bound states decaying to electron and photon continua with the two continua also weakly coupled to each other. A master equation describing the time evolution of the atomic system is derived, and its exact solution under arbitrary initial conditions is given. The effect of radiative decay on the Fano profiles and photoelectron spectra is analyzed in detail. The time development of the system is also examined. The radiative decay of the autoionizing state and the unperturbed continuum changes the spectra in a significant way. The characteristics of the spectra are correlated with the dressed states (with complex energies) of the system. The changes in the structure of the dressed states as a function of the system parameters such as the spontaneous-emission rate and laser intensity are discussed in detail.