非傍轴高斯光束通过方环硬边光阑的传输特性研究

Vectorial Nonparaxial Propagation Equation of Gaussian Beams in the Presence of an Annular Aperture

利用矢量Rayleigh积分公式研究了非傍轴高斯光束通过方环硬边光阑的传输,得到了衍射场分布的解析表达式。和傍轴传输相比较,该结果具有更广泛的适用性。以桶中功率为光束质量评价函数,讨论了遮拦比、截断参数对远场光束质量的影响。结果表明,环形光阑的尺寸决定着非傍轴光束远场能量分布的集中程度,截断参数和遮拦比的增大都会导致非傍轴高斯光束衍射效应增强,从而远场能量发散。

Vectorial Rayleigh integral formula is employed to study the nonparaxial propagation of Gaussian through an annular aperture, Analytical expression of diffractive field is deducted. The result is more applicable compared with that of pa raxial propagation. By the merit functions of PIB, the effects of abscured ratio and truncation parameter on beam quality are discussed in detail. Analysis results show that energy convergence of nonparaxial beam in the far field is determined by the dimension of the annular aperture, Diffractive effects of nonparaxial beam will be enhanced by increasing both abscured ratio and truncation parameter, which is also represented by the energy divergence in the far field.