矢量可控空心光束的非傍轴传输

Nonparaxial Propagation of Vectorial Controllable Dark-hollow Beams

提出了矢量可控空心光束概念,可控空心光束可以很好地描写中心光强不完全为零的圆对称空心光束,具有可用多个参量来控制中央暗斑尺寸、形式简单易于分析、其传输变换特性更接近于实际等特点。利用矢量瑞利-索未菲衍射积分公式,导出了矢最可控空心光束的非傍轴传输解析公式,从所得结果可退化得到傍轴近似结果。利用导出的公式计算分析了矢量可控空心光束在自由空间的非傍轴传输特性,并与傍轴结果进行了比较分析。结果表明矢量可控空心光束在近场很好地保持其空心光场分布特性;参量f和传输距离决定了矢量可控空心光束的非傍轴特性。

The concept of vectorial controllable dark-hollow （CDH） beams is proposed. The CDH beams can be used to describe circular hollow beam whose axial intensity is not entirely equal to zero. This model has many interesting characteristics that the central dark size of beam can be controlled easily by various parameters, the form simple and easy analysis, propagation properties approach actual case and so on. On the basis of vectorial Rayleigh-Sommerfeld formulas, the nonparaxial propagation analytical formulas of vectorial CDH beams are derived. The paraxial approximation is dealt with as special cases of our general results. By using the derived formulae, the propagation properties of vectorial CDH beams in free space are illustrated and analyzed comparatively with numerical examples. The results show that the vectorial CDH beams keep the hollow intensity distribtuon in the near field and the f parameter and propagation distance play the important role in determining their nonparaxiality.