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

Laser Physics

Spectrum of high harmonics generated by two-color circularly polarized laser field in atomic media

A V Andreev, Sergey Yu Stremoukhov, Olga A. Shoutova

Published Sep 10, 2020• 4 citations
Publisher

Abstract

Abstract Here we discuss the new effects in the light-atom interaction of an atom and two-colour ( ω , 2 ω ) elliptically polarized femtosecond pump beams. We show that the spectrum of atomic response does not include the signal at summary frequency ( ω + 2 ω ) and its harmonics when the frequency components of the pumping field are counter-rotating and the atom is in s -ground state. In the case when the ground state of the atom is p -state ( l = 1), these components vanish in the response spectrum of the longitudinal atomic current. In both cases, the suppression of the summary frequency is accompanied by the suppression of signal at THz frequency.

DOI
10.1088/1555-6611/abaefd

Related papers

Discrete exited states influence on the harmonics spectrum generated in two-colour laser fields

Sergey Yu Stremoukhov, A V Andreev

Abstract The contribution of excited discrete atomic levels to the generation of high- and low-order harmonics in the interaction of a single atom with a two-color laser field has been studied for the first time. The studies were carried out for two types of atoms with different symmetry of the ground state wave functions (Ag, Ne) and for a two-color laser field consisting of the linearly polarized fundamental and second harmonics of Ti:Sa laser ( ω + 2 ω ). The angle between the polarization of the ω + 2 ω laser field components is varied. A significant effect of the symmetry of populated excited levels on the polarization characteristics of the generated harmonics is shown. A new method of control over the polarization state of the generated radiation is proposed.

Laser Physics Letters•Dec 1, 2019•4 citations

Longitudinal Current Induced by a Plane Electromagnetic Wave in a Single Atom

A. V. Andreev, Sergey Yu Stremoukhov, О. А. Шутова

The change in the polarization state of the atomic response due to the appearence of the longitudinal component, which has been predicted in [A. Andreev, S. Stremoukhov, and O. Shoutova, Europhys. Lett. 120 , 14003 (2017)], has been studied. The dependence of the vector properties of the atomic current induced in an atom with unit angular momentum in the ground state on the properties of a two-color laser field with orthogonally polarized components has been analyzed. It has been shown that the variation of the delay time between the frequency components of the laser field makes it possible to efficiently control the polarization of the components of the atomic response field. The effect of the mutual orientation of the electric component of the laser field and the angular momentum of the atom on the longitudinal component of the atomic current and on the polarization properties of the generated radiation has been demonstrated.

Journal of Experimental and Theoretical Physics•Jul 1, 2018•6 citations

Polarization response of interacting atomic systems in an intense resonance laser field

A. V. Gulyaev, Olga V. Tikhonova

The dynamics and quantum correlations are studied in a system of two interacting atoms in a resonance femtosecond laser field. The polarization response of a medium consisting of such pairs of interacting atoms is analyzed. Regimes are found in which the polarization response of the medium under study contains the intense component at a tunable low frequency. It is shown that the dipole response of the medium can be suppressed using the entanglement effect and symmetry properties of collective atomic states.

Journal of Experimental and Theoretical Physics•May 1, 2012•0 citations

Effects of static magnetic field, driving laser strength and polarization on the coherent properties of a microwave mediated four-level tripod-type atomic system

Aparajita Das, Md. Mabud Hossain

Abstract In this theoretical work, we study the optical behaviour of a microwave driven four-level tripod-type atomic system, configured by Zeeman sub-levels in D 1 line of 87 Rb atom. The non-optical microwave field (L) reasonably assists the optical pumping by a linearly polarized (π) laser field (P1) and a right-handed circularly polarized (σ +) laser field (P2), in presence as well as absence of a static magnetic field (MF). The optical responses of the system to the left-handed circularly polarized (σ −) optical probe laser field (Pr) under three specific P1-P2 strength conditions depict substantial variations in the Doppler-free and Doppler-broadened absorption peaks, accompanied with single EIT or double EIT windows. The origin of Doppler-free Pr absorption peaks are explained by analyzing the resonant poles for the scanning Pr which attribute to the decaying-dressed-states. Perceptible changes of resonant pole positions on the complex planes of the poles w. r. t. the applied MF and L signify that one can externally alter the optical responses of the medium. The related Pr dispersion and its controllability are discussed as well. It is found that the interaction length of the Doppler-free medium has a prominent effect on the Pr absorption and transmission when both MF and L are present in the medium. Furthermore, we have shown the modifications in the Doppler-free Pr absorption profiles in presence of MF and L by considering P2 as an elliptically polarized laser field. Interestingly, Pr absorption turns into Pr gain at suitable polarization rotation angles of the elliptically polarized P2 field for different P1-P2 strength ratios.

Physica Scripta•Jan 10, 2023•2 citations

Femtosecond pulse propagation in a medium of two-level atoms

Anatoli V. Andreev, Alexander B. Kozlov

The interaction of femtosecond pulse with an extended medium of the two-level atoms or molecules is considered. It is shown that in the ultrahigh intensity layer field the atomic response is extremely nonmonochromatic due to the nonlinearity appropriate to the two-level system. The theoretical analyses shows that the two-level system tends to the generation of harmonics of the driving field. The results of the computer simulations show that in the ultrahigh fields the spectrum of the medium response is unusually broad in comparison with that for the fields of moderate intensity.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 5, 1999•2 citations

Control for atom response in multicomponent laser fields

A. V. Andreev, Sergey Yu Stremoukhov, Olga A. Shoutova

A theory of the nonlinear optical response of an atom interacting with a superposition of arbitrarily polarized fields is developed. The theory is based on the analytical solution of the boundary-value problem for an electron moving in a spherically symmetric intraatomic field and in the field of an external electromagnetic field. By means of the example of an argon atom interacting with a bichromatic field formed by the first and second harmonics of a Ti:sapphire laser, it is shown that, when an atom interacts with the field of two polarized pulses the polarization directions of which are not collinear, the response spectrum significantly depends on the laser radiation parameters—the duration and intensity of pulses, the time of delay between them, and the angle between the directions of polarization vectors. Generation of THz radiation is shown to be possible in the ionization-free regime due to intraatomic nonlinearity.

Optics and Spectroscopy•Mar 1, 2012•1 citation
Abstract Here we discuss the new effects in the light-atom interaction of an atom and two-colour ( ω , 2 ω ) elliptically polarized femtosecond pump beams. We show that the spectrum of atomic response does not include the signal at summary frequency ( ω + 2 ω ) and its harmonics when the frequency components of the pumping field are counter-rotating and the atom is in s -ground state. In the case when the ground state of the atom is p -state ( l = 1), these components vanish in the response spectrum of the longitudinal atomic current. In both cases, the suppression of the summary frequency is accompanied by the suppression of signal at THz frequency.
Abstract The contribution of excited discrete atomic levels to the generation of high- and low-order harmonics in the interaction of a single atom with a two-color laser field has been studied for the first time. The studies were carried out for two types of atoms with different symmetry of the ground state wave functions (Ag, Ne) and for a two-color laser field consisting of the linearly polarized fundamental and second harmonics of Ti:Sa laser ( ω + 2 ω ). The angle between the polarization of the ω + 2 ω laser field components is varied. A significant effect of the symmetry of populated excited levels on the polarization characteristics of the generated harmonics is shown. A new method of control over the polarization state of the generated radiation is proposed.
The change in the polarization state of the atomic response due to the appearence of the longitudinal component, which has been predicted in [A. Andreev, S. Stremoukhov, and O. Shoutova, Europhys. Lett. 120 , 14003 (2017)], has been studied. The dependence of the vector properties of the atomic current induced in an atom with unit angular momentum in the ground state on the properties of a two-color laser field with orthogonally polarized components has been analyzed. It has been shown that the variation of the delay time between the frequency components of the laser field makes it possible to efficiently control the polarization of the components of the atomic response field. The effect of the mutual orientation of the electric component of the laser field and the angular momentum of the atom on the longitudinal component of the atomic current and on the polarization properties of the generated radiation has been demonstrated.
The dynamics and quantum correlations are studied in a system of two interacting atoms in a resonance femtosecond laser field. The polarization response of a medium consisting of such pairs of interacting atoms is analyzed. Regimes are found in which the polarization response of the medium under study contains the intense component at a tunable low frequency. It is shown that the dipole response of the medium can be suppressed using the entanglement effect and symmetry properties of collective atomic states.
Abstract In this theoretical work, we study the optical behaviour of a microwave driven four-level tripod-type atomic system, configured by Zeeman sub-levels in D 1 line of 87 Rb atom. The non-optical microwave field (L) reasonably assists the optical pumping by a linearly polarized (π) laser field (P1) and a right-handed circularly polarized (σ +) laser field (P2), in presence as well as absence of a static magnetic field (MF). The optical responses of the system to the left-handed circularly polarized (σ −) optical probe laser field (Pr) under three specific P1-P2 strength conditions depict substantial variations in the Doppler-free and Doppler-broadened absorption peaks, accompanied with single EIT or double EIT windows. The origin of Doppler-free Pr absorption peaks are explained by analyzing the resonant poles for the scanning Pr which attribute to the decaying-dressed-states. Perceptible changes of resonant pole positions on the complex planes of the poles w. r. t. the applied MF and L signify that one can externally alter the optical responses of the medium. The related Pr dispersion and its controllability are discussed as well. It is found that the interaction length of the Doppler-free medium has a prominent effect on the Pr absorption and transmission when both MF and L are present in the medium. Furthermore, we have shown the modifications in the Doppler-free Pr absorption profiles in presence of MF and L by considering P2 as an elliptically polarized laser field. Interestingly, Pr absorption turns into Pr gain at suitable polarization rotation angles of the elliptically polarized P2 field for different P1-P2 strength ratios.
The interaction of femtosecond pulse with an extended medium of the two-level atoms or molecules is considered. It is shown that in the ultrahigh intensity layer field the atomic response is extremely nonmonochromatic due to the nonlinearity appropriate to the two-level system. The theoretical analyses shows that the two-level system tends to the generation of harmonics of the driving field. The results of the computer simulations show that in the ultrahigh fields the spectrum of the medium response is unusually broad in comparison with that for the fields of moderate intensity.
A theory of the nonlinear optical response of an atom interacting with a superposition of arbitrarily polarized fields is developed. The theory is based on the analytical solution of the boundary-value problem for an electron moving in a spherically symmetric intraatomic field and in the field of an external electromagnetic field. By means of the example of an argon atom interacting with a bichromatic field formed by the first and second harmonics of a Ti:sapphire laser, it is shown that, when an atom interacts with the field of two polarized pulses the polarization directions of which are not collinear, the response spectrum significantly depends on the laser radiation parameters—the duration and intensity of pulses, the time of delay between them, and the angle between the directions of polarization vectors. Generation of THz radiation is shown to be possible in the ionization-free regime due to intraatomic nonlinearity.