论文标题
n $ _2^+$ lasing：在旋转连贯性的情况下获得和吸收
N$_2^+$ Lasing: Gain and Absorption in the Presence of Rotational Coherence
论文作者
论文摘要
我们模拟了在分子氮离子中的泵探针实验，对旋转波包动力学的影响特别感兴趣。我们的计算表明，通过强烈的短无谐振脉冲在n $ _2^+$中的旋转波数据包的连贯制备导致对随后从$ b^2σ_U^+\ rightArrow x^2σ_g^+$ transitions的转变的调节。我们使用密度矩阵理论对这种泵送和排放的动力学进行建模，以描述n $ _2^+$动力学和麦克斯韦波方程，以建模种子脉冲传播。我们表明，延迟种子脉冲的增益和吸收取决于泵籽延迟，即泵脉冲激发的旋转一致性可以调节延迟种子脉冲的增益和吸收。此外，我们证明了氮离子的相干旋转动力学会导致激光无电子反转。
We simulate the pump-probe experiments of lasing in molecular nitrogen ions with particular interest on the effects of rotational wave-packet dynamics. Our computations demonstrate that the coherent preparation of rotational wave packets in N$_2^+$ by an intense short non-resonant pulse results in a modulation of the subsequent emission from $B^2Σ_u^+ \rightarrow X^2Σ_g^+$ transitions induced by a resonant seed pulse. We model the dynamics of such pumping and emission using density matrix theory to describe the N$_2^+$ dynamics and the Maxwell wave equation to model the seed pulse propagation. We show that the gain and absorption of a delayed seed pulse is dependent on the pump-seed delay, that is, the rotational coherences excited by the pump pulse can modulate the gain and absorption of the delayed seed pulse. Further, we demonstrate that the coherent rotational dynamics of the nitrogen ions can cause lasing without electronic inversion.
