利用德拜矢量积分理论,推导了部分偏振高斯光束经大数值孔径透镜聚焦的光场和光强表达式,并用数值计算分析了不同偏振度下高斯光束的大数值孔径聚焦特性。研究发现大数值孔径聚焦时,部分偏振高斯光束在焦平面的总光强及各分量光强分布随偏振度变化而变化。研究还表明,焦平面上的光强分布形状还与聚焦透镜的数值孔径角取值有关。因此通过控制入射光束偏振度和聚焦透镜数值孔径角的取值,可以改变部分偏振高斯光束经大数值孔径透镜的聚焦光场分布。

Based on vectorial Debye integral,the light field and intensity distribution expressions are presented when partially polarized Gaussian beams pass through a high numerical-aperture objective. Numerical calculations are taken to analyze the tightly focusing properties of partially polarized Gaussian beams with various degrees of polarization. The research results show that the total intensity distribution and each direction components of partially polarized Gaussian beams on the focal plane will change with the change of polarization. It is also found that the values of the maximal angle of the high numerical-aperture objective will influence the total intensity on the focal plane. Therefore,the intensity distribution of partially polarized Gaussian beam on the focal plane can be controlled by adjusting the polarization and the maximal angle of the high numerical-aperture objective.