© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)

Coherent control of ionization using two-color field

Shangqing Gong, Haitao Wu, Zhongyang Wang, Zhizhan Xu

Published Jan 20, 2003• 0 citations

Abstract

The coherent control of ionization using two-color field has received considerable attention in recent years. In the case of two color laser field, because of additional degrees of freedom such as relative phase, intensities and relative polarizations, etc., the ionization of the system can be influenced significantly. In most papers, they investigated the ionisation behavior of system by using the combinations of the fundamental laser field (/spl omega/) and its second (2/spl omega/) or third (3/spl omega/) harmonic field. To our knowledge, a comparison between /spl omega/-2/spl omega/ and /spl omega/-3/spl omega/ is seldom dealt with. In this paper, we choose the combination of the fundamental laser field (/spl omega/) with its second (2/spl omega/) or third (3/spl omega/) harmonic field, and investigate the ionization of the system for the two kinds of combinations.

DOI: 10.1109/cleopr.1999.817882

Related papers

Coherent control of ionization in two-color laser fields: a comparison between ω–2ω and ω–3ω combinations

Shangqing Gong, Haitao Wu, Zhongyang Wang +1 more

Physics Letters A•Jul 1, 2000•5 citations

Phase control in two-colour multiphoton ionization

M. Protopapas, P. L. Knight

We examine the excitation dynamics of a model atom excited by a two-colour laser field. Here the two colours or frequencies are the fundamental and its third harmonic. The atomic model consists of two bound states which are near-resonantly coupled by a three-photon excitation by the fundamental and a one-photon excitation by the third harmonic, and a structureless continuum. We investigate how the laser parameters (intensity and frequency) and the relative phase between the two colours affects the degree of phase modulation in the ionization signal. We compare our findings from this simple model atom with those from more realistic atomic models by carrying out numerical integration of the hydrogenic Schrodinger equation in both one and three dimensions.

Journal of Physics B Atomic Molecular and Optical Physics•Oct 28, 1995•33 citations

Coherent control of spectral effects with two-color ultrashort laser pulses: a comparison between ω-2ω and ω-3ω combinations

Xiaohong Song, Shangqing Gong, Zhizhan Xu

Using the full Maxwell-Bloch equations which avoid the limitations of slowly-varying-envelope approximation and the rotating--wave approximation as ultrashort pulses are considered, we investigate the coherent control of spectra effects with two color few-cycle laser pulses. We demonstrate that the interference effect of the two laser pulses can substantially modify the behavior of the spectra, higher spectral components can occur even for small area pulses. Moreover, comparing the ω-2ω combination with the ω-3ω scenario, we find due to the deferent superposition of the two kinds of combined laser pulses, the features of these higher spectral components can be much different.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 28, 2005•0 citations

Two-color coherent control of atomic multiphoton ionization with high-order harmonics: time-dependent Schrödinger equation treatment

Richard Taïeb, Valérie Vëniard, A. Maquet

We present a theoretical study of the main characteristics of two-color photoionization spectra obtained when atoms are subjected to an intense radiation pulse containing the fundamental of an infrared laser and one of its higher harmonics. The frequency of the latter is chosen to be high enough that the atom can be ionized by a single photon. The calculation is performed by numerical integration of the time-dependent Schrödinger equation for a (three-dimensional) hydrogen atom. We present the general properties of the spectra and angular distributions as well as the possible occurrence of interferences between the laser-assisted process and above-threshold ionization. Our results indicate that such interference effects, which can lead to partial coherent control of the photoionization process, can be observed at moderate laser intensities within the reach of currently operated laser and harmonic sources.

Journal of the Optical Society of America B•Feb 1, 1996•25 citations

Phase Dependence of Intense Field Ionization: A Study Using Two Colors

Douglass W. Schumacher, Frederick Weihe, Harm Geert Muller +1 more

We present the first measurement of the ionization rate from above-threshold ionization (ATI) in an optical field whose phase dependence is known and controllable. Our method uses a harmonic two-color light field with a calibrated phase difference between the $1\ensuremath{\omega}$ and $2\ensuremath{\omega}$ fields. Our measurements confirm many of the predictions of recent semiclassical theories, but show an important discrepancy: An asymmetry in the ATI rates relative to the sign of the two-color phase difference supports recently suggested modifications to the models to include electron-core rescattering during ionization.

Physical Review Letters•Sep 5, 1994•197 citations

Coherent control of multiphoton ionization of lithium atoms by a bichromatic laser field

Silva Mezinska, Alexander Dorn, Thomas Pfeifer +1 more

We demonstrate a left-right asymmetry control of the photoelectron angular distribution in multiphoton ionization of Li atoms by a bichromatic laser field. By delaying the fundamental (780 nm) and its second harmonic relative to each other in steps of 130 attoseconds, we can vary the relative phase between the two laser fields with subwavelength accuracy and thereby steer the ejected electrons. Good agreement is found between the measurements and calculations at the appropriate intensities of the two harmonics. Published by the American Physical Society 2024

arXiv:2405.10420•Physical Review A•Jul 17, 2024•2 citations

The coherent control of ionization using two-color field has received considerable attention in recent years. In the case of two color laser field, because of additional degrees of freedom such as relative phase, intensities and relative polarizations, etc., the ionization of the system can be influenced significantly. In most papers, they investigated the ionisation behavior of system by using the combinations of the fundamental laser field (/spl omega/) and its second (2/spl omega/) or third (3/spl omega/) harmonic field. To our knowledge, a comparison between /spl omega/-2/spl omega/ and /spl omega/-3/spl omega/ is seldom dealt with. In this paper, we choose the combination of the fundamental laser field (/spl omega/) with its second (2/spl omega/) or third (3/spl omega/) harmonic field, and investigate the ionization of the system for the two kinds of combinations.

We examine the excitation dynamics of a model atom excited by a two-colour laser field. Here the two colours or frequencies are the fundamental and its third harmonic. The atomic model consists of two bound states which are near-resonantly coupled by a three-photon excitation by the fundamental and a one-photon excitation by the third harmonic, and a structureless continuum. We investigate how the laser parameters (intensity and frequency) and the relative phase between the two colours affects the degree of phase modulation in the ionization signal. We compare our findings from this simple model atom with those from more realistic atomic models by carrying out numerical integration of the hydrogenic Schrodinger equation in both one and three dimensions.

Using the full Maxwell-Bloch equations which avoid the limitations of slowly-varying-envelope approximation and the rotating--wave approximation as ultrashort pulses are considered, we investigate the coherent control of spectra effects with two color few-cycle laser pulses. We demonstrate that the interference effect of the two laser pulses can substantially modify the behavior of the spectra, higher spectral components can occur even for small area pulses. Moreover, comparing the ω-2ω combination with the ω-3ω scenario, we find due to the deferent superposition of the two kinds of combined laser pulses, the features of these higher spectral components can be much different.

We present a theoretical study of the main characteristics of two-color photoionization spectra obtained when atoms are subjected to an intense radiation pulse containing the fundamental of an infrared laser and one of its higher harmonics. The frequency of the latter is chosen to be high enough that the atom can be ionized by a single photon. The calculation is performed by numerical integration of the time-dependent Schrödinger equation for a (three-dimensional) hydrogen atom. We present the general properties of the spectra and angular distributions as well as the possible occurrence of interferences between the laser-assisted process and above-threshold ionization. Our results indicate that such interference effects, which can lead to partial coherent control of the photoionization process, can be observed at moderate laser intensities within the reach of currently operated laser and harmonic sources.

We present the first measurement of the ionization rate from above-threshold ionization (ATI) in an optical field whose phase dependence is known and controllable. Our method uses a harmonic two-color light field with a calibrated phase difference between the $1\ensuremath{\omega}$ and $2\ensuremath{\omega}$ fields. Our measurements confirm many of the predictions of recent semiclassical theories, but show an important discrepancy: An asymmetry in the ATI rates relative to the sign of the two-color phase difference supports recently suggested modifications to the models to include electron-core rescattering during ionization.

We demonstrate a left-right asymmetry control of the photoelectron angular distribution in multiphoton ionization of Li atoms by a bichromatic laser field. By delaying the fundamental (780 nm) and its second harmonic relative to each other in steps of 130 attoseconds, we can vary the relative phase between the two laser fields with subwavelength accuracy and thereby steer the ejected electrons. Good agreement is found between the measurements and calculations at the appropriate intensities of the two harmonics. Published by the American Physical Society 2024