高度聚焦系统中径向偏振光束强焦斑消失

该文通过与线性偏振光束图形比较,研究径向偏振光束的横向焦斑尺寸的大小.入射光圈是内径可调的光圈.即使只考虑纵向场分量,径向偏振光束焦斑尺寸也可能比在同一个横向的线性偏振光束大.随着数值孔径和环形光圈内径的增大,焦斑尺寸会明显变大,在这个范围内,径向偏振光束纵向场分量优于横向的线性偏振光束纵向场分量.因此,对于横向强聚焦,线性偏振光束优于径向偏振光束.

Sharper Focus Disappear for Radially Polarized Beam in Highly Focusing System

Focal size in one transverse direction of focusing radially polarized vector beam（RPB） is investiga- ted numerically by comparing graphically it with that of linearly polarized beam（LPB）. The incident aperture is annular with tunable inner radius. It was found that even only longitudinal field component is considered, and its focal size may be bigger than that in one transverse direction of focusing LPB. On increasing numerical aperture and inner radius of the annular aperture, the range, within which longitudinal field component of RPB outperforms one transverse direction of LPB, extends very considerably. Therefore, if one transverse sharp fo- cus is desirable, the focusing RPB does not outperform than LPB. Especially, focal size under different condi- tions is given by tables with wavelength unit, which may be used friendly in practice applications.