非傍轴高斯光束传输特性的研究

Propagation characteristics of nonparaxial Gaussian beams

基于非傍轴矢量光束横截面上光强的严格定义〈Sz〉,采用桶中功率定义光束的束宽、远场发散角以及M2因子.以非傍轴矢量高斯光束为例,对光束的传输特性进行了详细的理论分析和数值计算,并与非傍轴标量理论的结果进行了比较分析.研究表明,光源半宽ω0/λ<1时,传输特性的矢量描述与非傍轴标量描述有显著差别,随着ω0/λ的增大,两者趋于一致,并逐步过渡到傍轴标量近似.

Based on the rigorous definition of light intensity of nonparaxial vectorial beams in the transverse plane, beam width, far-field divergence angles and M2 factors are defined by the power in the bucket. Taking nonparaxial vectorial Gaussian beam as an example, the detailed theoretical analyses and numerical calculations about the propagation characteristics are performed, and the results are compared with those from the nonparaxial scalar theory. Showing that when the half width of light source ω0 is less than λ, there are obvious differences between the propagation characteristics described by the nonparaxial scalar and the vectorial theory, and their propagation characteristics tend to be consistent with ω0 increasing, change to that obtained in the paraxial scalar approximation gradually.