傍轴光束在单轴左手介质中传输的矢量性质

The vectorial properties of paraxial beams propagating in uniaxial left-handed materials

研究了沿光轴入射的傍轴光束在单轴左手介质中传输的矢量性质.通过平面角谱的方法得到了横电(TE)波和横磁(TM)波在单轴左手介质中传输的严格解,并得到了傍轴近似下的矢量传输模型.利用这一模型,分析得到垂直于光轴方向不同偏振态的入射光束在单轴左手介质中同时激发横向场和低阶纵向场.如果单轴左手介质的介电常数张量在沿垂直于光轴方向上的两元素不相等,同时磁导率张量在沿垂直于光轴方向上的两元素也不相等(即z方向为光轴方向,x≠y,μx≠μy),那么入射光束激发的横向场的分布与入射光束的初始场分布和偏振态有关,而纵向场的分布与入射光束的偏振态无关,只决定于入射光束的初始场分布.

The vectorial properties of paraxial beams propagating along the optical axis of uniaxial left-handed materials are studied. On the basis of a suitable plane-wave angular spectrum representation of the electromagnetic field, we obtain the analytical expressions of the optical field. The longitudinal component is expressible in terms of the firest correction of the transverse field. Moreover, the transverse field varies when either of the polarization and the distributing of the initial electromagnetic field is changed. But the longitudinal compenent is only dependent on the initial distributing of the field.