基于矢量光场调控的宽波带全晶体型光瞳滤波器

Crystal-Based Pupil Filter for Manipulation of the Vectorial Field in the Broad Band

基于复合波片消色差设计方法，结合矢量光场衍射受限的大数值孔径聚焦理论，以600 nm 为中心波长，提出了一种适用于宽波带的全晶体型光瞳滤波器。该滤波器由三片具有同心分区环带的复合延迟波片构成，每分区波片具有各自的方位角及环带参数，且相邻环带光轴垂直。在轴对称偏振矢量光场入射下，通过调节光瞳滤波器的方位角，经聚焦后，在550-650 nm 波长范围内，均可获得轴向焦深的扩展、横向压缩的光针场以及衍射受限的三维光管场。研究结果表明，该光瞳滤波器在100 nm 波段内实现了宽波带矢量光场的调控，这种光瞳滤波器的设计对发展矢量光场的聚焦理论和拓展矢量光在宽波带光场应用方面有重要意义。

Based on the achromatic principle of composite wave plate and diffraction-limited theory of the tight focusing of the vectorial field, a pupil filter is presented for the focusing of the broadband vectorial field with the central wavelength of 600 nm. This filter is combined of three segmented wave plates, each of which is divided into four concentric belts with optimized radial parameters and azimuth angle. The optical axis of the two adjacent belts is vertical. For the incident vectorial beam with wavelength from 550 nm to 650 nm, the desired specially focused field with extended depth of focus, such as optical needle field with compressed radial width and diffraction-limited tube filed, can be achieved. The result shows that this filter can be effectively used as an effective manipulator for the vector beam with wide waveband in the 100 nm band. This achromatic pupil filer will be beneficial for the development of the focusing theory and applied technology about the wideband vectorial field.