介绍了在特殊激光光束非线性传输特性方面的研究。主要包括具有横向效应的超短脉冲的时空演化、半导体量子阱系统的自诱导传输现象及电磁诱导透明介质中的共振多极矢量孤子。由于横向效应,包络面积为2nπ双曲正割脉冲在传输过程中会发生形变甚至分裂,随后发生月牙形脉冲的干涉,随着传输距离的增加干涉相长和自聚焦现象在横向轴上及其两侧出现。超短脉冲在量子阱中传输时,传统的面积定理失效,通过定义有效面积,实现了有效面积为2π的自感应传输。研究了四能级原子系统中共振多极矢量孤子的形成与传输,弱探测矢量场的两个偏振成分相互俘获,形成稳定的耦合态并实现了非常低的传输损耗。

We investigate intersubband Rabi flopping in modulation-doped semiconductor quantum wells with and without the propagation effects, respectively. It is shown that propagation effects have a larger impact on Rabi flopping than the nonlinearities rooted from electron-electron interactions in multiple quantum wells. By using ultrashort \pi pulses, an almost complete population inversion exists if the propagation effects are not considered; while no complete population inversion occurs in the presence of propagation effects. Furthermore, the magnitude of the impact of propagation effects may be controlled by varying the carrier density.

In an open /\ type system with the spontaneously generated coherence (SGC), when the probe and driving fields have different frequencies, the switching of the group velocity of the probe pulse from subluminal to superluminal is realized not only by adjusting values of the relative phase between the probe and driving fields but also by varying values of the incoherent pumping rate. For the subluminal propagation, the system always exhibits the probe absorption, however, the superluminal propagation is always companied with gain of the probe field.

A way resulting in lasing without inversion (LWI) in an open resonant Λ-type system from a nonlinear dynamics viewpoint is investigated. The destabilization of the non-lasing solution can occur not only through pitchfork bifurcation, giving rise to continuous wave LWI, but also through Hopf bifurcation, giving rise to self-pulsing LWI. This is much different from that of the corresponding closed resonant Λ-type system in which the destabilization of the non-lasing solution can occur only through pitchfork bifurcation. The effects of the unsaturated gain coefficient, cavity loss coefficient, atomic injection and exit rates on the two bifurcations are discussed.

It is shown that in an open V-type atomic system without incoherent pumping, the spontaneously generated coherence (SGC) can not only lead to lasing with inversion but also lead to lasing without inversion (LWI) including at resonance of the driving and probe fields. This conclusion is much different from that obtained in the corresponding closed V-type system.