论文标题
使用双拉曼单线和双重光线旋转方案的离轴光学涡流
Off-axis optical vortices using double-Raman singlet and doublet light-matter schemes
论文作者
论文摘要
我们研究了在双兰曼增益原子培养基内传播的离轴光涡流的形成。原子与两个弱探头场以及两个可以携带轨道角动量（OAM）的强泵梁相互作用。我们考虑的情况只有一个强泵激光器携带oAM。与此物质结合的探针场的特定叠加表明可以形成带有移动轴的特定光学涡旋。这种离轴涡流可以根据两光子失调的值而在培养基内传播介质。当泵场的能量转移到探针场时，掌光涡流与扩增相关。外围涡旋的位置可以通过泵场的OAM和强度来操纵。我们表明，当第二探针场的振幅在原子云的开头时为零时，各个探测器梁和泵场之间的交换是可能的。该模型扩展到更复杂的双重拉曼双线，与四个泵场相互作用。与双射线单词相反，现在即使对于零两光片失调，也可以产生离轴亚轴下或静光光学涡旋的产生。
We study the formation of off-axis optical vortices propagating inside a double-Raman gain atomic medium. The atoms interact with two weak probe fields as well as two strong pump beams which can carry orbital angular momentum (OAM). We consider a situation when only one of the strong pump lasers carries an OAM. A particular superposition of probe fields coupled to the matter is shown to form specific optical vortices with shifted axes. Such off-axis vortices can propagate inside the medium with sub- or superluminal group velocity depending on the value of the two-photon detuning. The superluminal optical vortices are associated with the amplification as the energy of pump fields is transferred to the probe fields. The position of the peripheral vortices can be manipulated by the OAM and intensity of the pump fields. We show that the exchange of optical vortices is possible between individual probe beams and the pump fields when the amplitude of the second probe field is zero at the beginning of the atomic cloud. The model is extended to a more complex double Raman doublet interacting with four pump fields. In contrast to the double-Raman-singlet, now the generation of the off-axis sub- or superluminal optical vortices is possible even for zero two-photon detuning.
