三环位相型光瞳滤波器的横向超分辨与轴向焦深扩展

Transverse superresolution and extended axial focal depth realized by three-zone annular phase pupil filter

用矢量衍射方法分析了线偏振光入射到带有三环位相型光瞳滤波器的高数值孔径物镜时,焦点的轴向和横向光强分布.数值模拟结果表明,高数值孔径物镜聚焦时需同时考虑光强的轴向和横向分布.通过加入三环位相光瞳滤波器,在实现横向超分辨的同时实现了光学系统轴向焦深扩展和轴向光强分布平坦化,并且位相调制深度变化时,会出现轴向焦移现象.对三环位相光瞳滤波器结构进行了优化,得出了优化结果.

When linearly polarized light is focused using a high numerical aperture lens with three-zone annular phase pupil filter,vector diffraction method was applied to study the optical intensity distribution in transverse and axial directions. Numerical simulation results show that optical intensity distribution in transverse and axial directions need to be treated simultaneously. When three-zone annular phase pupil filter is added in front of a high numerical aperture lens,transverse super resolution,extended axial focal depth and flat-top focusing can be achieved at the same time. Furthermore,When phase modulation depth is changed,the phenomenon of axial focal shift can be found. The structure of three-zone annular phase pupil filter was optimized and the optimized results were given.