Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields

Abstract

We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel ionized N2 molecules at various driver wavelengths in the near- and mid-infrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground state and the excited states occur in strong laser fields. The couplings result in the population inversion between the ground and the excited states at the wavelengths near 800 nm, which is verified by our experiment by observing the amplification of a seed at ~391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.

18 pages, 4 figures

References in corpus (2)

• Recollision induced superradiance of ionized nitrogen molecules
• Attosecond control of electron dynamics in carbon monoxide

Cited by in corpus (24)

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• Near-resonant Raman amplification in the rotational quantum wavepackets of nitrogen molecular ions generated by strong field ionization
• Transient gain from $N_2^{+}$ in light filaments
• Coherent control of superradiance from nitrogen ions pumped with femtosecond pulses
• Amplification of intense light fields by nearly free electrons
• Role of rotational coherence in femtosecond-pulse-driven nitrogen ion lasing
• Electronic State Population Dynamics upon Ultrafast Strong Field Ionization and Fragmentation of Molecular Nitrogen
• Floquet-Landau-Zener interferometry: Usefulness of the Floquet theory in pulse-laser-driven systems
• Structured air lasing of N2+
• Exit momentum and instantaneous ionization rate of nonadiabatic tunneling ionization in elliptically polarized laser fields
• Photon retention in coherently excited nitrogen ions
• Coherence from multiorbital tunneling ionization of molecules
• Quantum erasing of laser emission in N${}_2^{+}$
• N${}_2^{+}$ Lasing: Gain and Absorption in the Presence of Rotational Coherence
• Control of ${\text{N}}_2^{+}$ Air Lasing
• Amplification of light pulses with orbital angular momentum (OAM) in nitrogen ions lasing
• Controlling the polarization of nitrogen ion lasing
• Electronic-vibrational dynamics and coherence in x-ray transient absorption of N2+ induced by strong-field ionization
• Ramsey interferometry through coherent $X^2{\Sigma }_g^{+}-A^2{\Pi }_u-B^2{\Sigma }_u^{+}$ coupling and population transfer in N${}_2^{+}$ air laser
• Revisiting self-seeding mechanism by generating vector ultraviolet N${}_2^{+}$ lasing
• Nonadiabatic theory for subcycle ionic dynamics in multielectron tunneling ionization
• Transient optical gain in strong-field-excited solids
• Lasing without population inversion in air
• Disentangle pathways in strong field molecular photoionization byangular distribution of dissociation fragments