理论和实验研究了径向偏振高阶贝塞尔-高斯涡旋光束在自由空间传输的光强分布和偏振特性.数值计算表明, 在无衍射区域, 随着传输距离的增加, 光强分布基本保持不变; 对于零阶光束, 其偏振态一直保持径向偏振不变; 对于高阶光束, 其偏振态发生变化, 由初始的径向偏振逐渐变为椭圆偏振和线偏振的杂化状态.实验上, 利用径向偏振转换器、螺旋相位板和轴棱锥元件产生了径向偏振高阶贝塞尔-高斯涡旋光束, 探测了其通过不同偏振片后的光强分布.实验结果与理论结果基本相符合.该研究也提供了一种产生杂化偏振矢量光束的方法.

The intensity distribution and polarization characteristics of the radially polarized high-order Bessel-Gaussian vortex beams propagating in free space were studied theoretically and experimentally. Through numerical calculation, with transmission distance increasing, the intensity distribution remains unchanged in the diffraction free area. For a zero order beam, the polarization state remains the same. But for a higher order light beam, the polarization state changes, and the initial radial polarization gradually changes into the hybrid polarization state including elliptical polarization and linear polarization. In the experiment, a radially polarized high-order Bessel -Gaussian vortex beam is produced by using the radial polarization converter, vortex phase plate and axicon element. The light intensity distributions of the beams passing through different polarizers are detected. By comparing the experimental results with the theoretical results, it is found that they are basically consistent. The study also provides a method to produce the hybrid polarized vector beams.