非傍轴矢量高斯光束

对傍轴近似下的光束传输变换问题进行了广泛的研究.但是,当光束有大的发散角或与波长相比拟的小光斑尺寸时,傍轴近似不再成立.已发展了多种非傍轴方法用以研究非傍轴光束的传输问题.对非傍轴光束的研究方法作了总结,使用角谱表示法和瑞利衍射积分公式对非傍轴矢量高斯光束的传输作了分析和比较.结果表明,基于瑞利衍射积分公式推导出的非傍轴矢量高斯光束在自由空间传输的解析公式在传输距离远大于波长时是严格的解析结果,并且在有光阑的情况下也是适用的.光束的非傍轴性主要由f参数决定,但当有光阑存在时,截断参数也对光束非傍轴行为产生影响.

Nonparaxial vectorial Gaussian beams

Beam propagation and transformation have been studied extensively within the framework of the paraxial approximation. This method is no longer valid for beams with a large divergence angle or a small spot size comparable with the wavelength. A variety of nonparaxial approaches have been developed to treat the propagation of nonparaxial beams. In this paper,the methods used to study nonparaxial beams are summarized. By using the angular spectrum representation method and Rayleigh diffraction integrals, the propagation of nonparaxial vectorial Gaussian beams was analyzed and compared. The result shows that the analytical expression for the propagation of nonparaxial vectorial Gaussian beams in free space based on the Rayleigh diffraction integrals provides the strict result for the case that the propagation distance is much larger than the wavelength and is also applicable to the apertured case. The beam nonparaxiality is mainly determined by the f parameter, but in the presence of an aperture, the truncation parameter additionally affects the beam nonparaxial behavior.