Theory of femtosecond strong field ion excitation and subsequent lasing in N2+ - Direction des applications militaires Accéder directement au contenu
Article Dans Une Revue New Journal of Physics Année : 2021

Theory of femtosecond strong field ion excitation and subsequent lasing in N2+

Résumé

Delayed cavity-free forward lasing at the wavelengths of 391 and 428 nm was observed in recent experiments in air or pure nitrogen pumped with an intense femtosecond laser pulse at wavelength of 800 nm. The mechanism responsible for the lasing is highly controversial. In this article we propose a model explaining the delayed lasing, which contains two parts: (i) ionization of neutral nitrogen molecules and subsequent excitation of nitrogen ions in a strong pump laser pulse, and (ii) coherent emission of excited ions due to the presence of long-lived polarizations maintained by a weak laser post-pulse and coupling simultaneously ground state X 2 Σ + g to states A 2 Π u and B 2 Σ + u of singly ionized nitrogen molecules N + 2. Two regimes of signal amplification are identified: a signal of a few picosecond duration at low gas pressures and a short (sub-picosecond) signal at high gas pressures. The theoretical model compares favorably with results obtained by different experimental groups.
Fichier principal
Vignette du fichier
Tikhonchuk_2021_New_J._Phys._23_023035.pdf (2.75 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03149138 , version 1 (22-02-2021)

Identifiants

Citer

V T Tikhonchuk, Y Liu, Rostyslav Danylo, Aurélien Houard, A Mysyrowicz. Theory of femtosecond strong field ion excitation and subsequent lasing in N2+. New Journal of Physics, 2021, 23 (2), pp.023035. ⟨10.1088/1367-2630/abd8bf⟩. ⟨hal-03149138⟩
148 Consultations
91 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More