矢量衍射理论的比较研究及标量近似的有效性  

A comparative study of vectorial diffraction theories and the validity of scalar approximation

作　　者：邓小玖[1] 李怀龙[1] 刘彩霞[1] 胡继刚[1] 王飞[1] 

机构地区：[1]合肥工业大学物理系,安徽合肥230009

出　　处：《量子电子学报》2007年第5期543-547,共5页Chinese Journal of Quantum Electronics

基　　金：教育部专项科研基金(011001B2);合肥工业大学科研发展基金(061001F)

摘　　要：光束束腰与波长相比拟时,标量近似已不再成立。以高斯光束的微小圆孔衍射为例,对矢量衍射场的级数解、非傍轴近似解以及精确解进行了详细的数值计算和比较研究。结果表明,对受硬边光阑限制的非傍轴光束,级数展开法适用于处理光束在近场区域的传播,而非傍轴近似解则适用于处理非近场区域光束的传播,具有一定的互补性。讨论了高斯光束圆孔衍射标量近似的有效性,当高斯光束的束腰半径、衍射孔孔径大于几个光波波长时,标量衍射理论是精确、有效的。It is well known that the scalar approximation is no longer valid for the beams with small spot size comparable with the wavelength. Detailed numerical calculations for the series expansion solution, non-paraxial approximation solution and exact solution of vectorial Gaussian beams diffracted at a small circular aperture are performed and compared; It is shown that the series expansion solution is valid in the near-field region, and the non-paraxial approximation solution is valid in the non-near-field region for the propagation of a non-paraxial beam diffracted by a small hard-edge aperture, .and they are compensated mutually. The validity of the scalar approximation of Gaussian beams diffracted at a circular aperture is discussed; the scalar diffraction theory is rigorous and valid when the waist width of a Gaussian beam and the aperture size is larger than several wavelengths.

关 键 词：物理光学 矢量衍射理论 高斯光束 圆孔衍射 有效性 

分 类 号：O436.1[机械工程—光学工程]