We investigate air lasing at 391 nm, induced by strong laser fields in a nitrogen glow discharge plasma. We generate forward air lasing on the – transition at 391 nm by irradiating an intense 35-fs, 800-nm laser in a pure nitrogen gas, finding that the 391-nm lasing quenches when the nitrogen gas is electrically discharged. In contrast, the 391-nm fluorescence measured from the side of the laser beam is strongly enhanced, demonstrating that this discharge promotes the population in the state. By comparing the lasing and fluorescence spectra of the nitrogen gas obtained in the discharged and laser-induced plasma, we show that the quenching of lasing is caused by the efficient suppression of population inversion between the and states of , in which a much higher population occurs in the state in the discharge plasma. Our results clarify the important role of population inversion in generating air lasing, and also indicate the potential for the enhancement of lasing via further manipulation of the population in the state in the discharged medium.

我们研究了由氮辉光放电等离子体中的强激光场诱导的 391 nm 空气激光。我们通过在纯氮气中照射强烈的 35-fs、800 - nm 激光，在 391 nm 处产生正向空气激光，发现当氮气放电时，391-nm 激光猝灭。相比之下，从激光束侧面测量的 391 nm 荧光被强烈增强，表明这种放电促进了该州的人口。通过比较在放电和激光诱导等离子体中获得的氮气的激光和荧光光谱，我们表明激光的猝灭是由有效抑制和之间的粒子数反转引起的。的状态，其中在放电等离子体中的状态中出现了更高的人口。我们的结果阐明了种群反转在产生空气激光中的重要作用，并表明通过进一步操纵放电介质中的状态种群来增强激光的潜力。