Lasing without population inversion in N2+

• DOI: 10.1063/1.5116898
• Publication Date: 2019-11-14T13:40:24Z
• Authors: A. Mysyrowicz; R. Danylo; A. Houard; V. Tikhonchuk; X. Zhang; Z. Fan; Q. Liang; S. Zhuang; L. Yuan; Y. Liu
• Keywords: Population inversion

We experimentally demonstrate the existence of long-lived coherent polarizations coupling simultaneously ground state X (X2Σg+) to excited states A (A2Πu) and B (B2Σu+) N2+ inside a plasma created by short intense laser pulse at 800 nm. This three-level V-scheme arrangement is responsible for strong optical gain without population inversion B–X transition 391.4 Simulations based on Maxwell-Bloch equations reproduce well kinetics pressure dependence gain.