基于偏振光相位调制的超衍射极限空间结构光研究
Sub-diffraction-limit spatially structured light pattern based on polarized beam phase modulation
摘要
Abstract
The sub-diffraction-limit spatially structured light patterns have attracted more and more attention for their important applications in many frontier scientific fields.The present paper aims at developing sub-diffraction-limit spatially structured beam patterns which might have great potential to improve the light performance in fields such as super resolution imagery,optical tweezer,micro/nano lithography,etc.Here,a variety of spatially structured beam patterns are obtained by the phase modulation of polarized beams and studied in detail experimentally and numerically.Firstly,a new kind of phase plate,which combines the merits of circular π and vortex 2π phase plates,is proposed based on the wave front design;it is composed of two spiral-shaped phase plates with their phases changing from 0 to 2π and-π to π,respectively.Later,the phase plate is applied to the circularly polarized Gaussian beam modulation in a high NA system.By combining a self-made circular π with a commercial vortex 2π phase plate,the designed new phase plate is implemented in the experiment.The morphology of the spatially structured light pattern,which is generated on the focal plane,is observed by a CCD camera in the experiment.The beam pattern presents a donut shape on the focal plane,while the dimension of the donut-shaped pattern becomes smaller as the imaging planc axially deviates from the focal plane.It is found that the beam patterns captured in experiment highly consist with the numerical simulation results carried out by the vectorial diffraction integral theory.It can be deduced that the spatially structured beam is capillary-shaped.Meanwhile,at the two ends of the capillary-shaped beam,the inner diameter is smaller than the diffraction limitation.Furthermore,the structured beam pattern presents a spatial voxel distribution with center and axis symmetry.Finally,the characteristics of the spatially structured beam patterns,which are generated by modulating circular,linear,radial and azimuthal polarized beams with the new designed phase plate,are analyzed and discussed in detail.It is found that for circular,linear,radial and azimuthal polarization,the full widths at half maximum (FWHMs)of the minimum dark spots in the horizontal direction are 0.31λ,0.32λ,0.24λ and 0.36λ,respectively.On the optical axis,the FWHMs of the dark spots created by linearly,radially and azimuthally polarized light,are 0.8λ,0.78λ and 0.76λ,respectively,and no axial intensity is found with circularly polarized beam incidence.关键词
相位调制/超衍射极限/结构光/衍射积分理论Key words
phase modulation/sub-diffraction limit/structured light/diffraction integral theory引用本文复制引用
袁强,赵文轩,马睿,张琛,赵伟,王爽,冯晓强,王凯歌,白晋涛..基于偏振光相位调制的超衍射极限空间结构光研究[J].物理学报,2017,66(11):18-26,9.基金项目
Project supported by Young Scientist Fund of the National Natural Science Foundation of China (Grant No.11504294),the National Natural Science Foundation of China (Grant No.61378083),the Major Research Plan of the National Natural Science Foundation of China (Grant No.91123030),the International Cooperation Foundation of the National Science and Technology Ministry of China (Grant No.2011DFA12220),the Youth Talent Plan of the Natural Science Foundation of Shaanxi Province of China (Grant No.2016JQ1030),and the Natural Science Foundation of Shaanxi Province of China (Grant Nos.14JS106,2013SZS03-Z01).国家自然科学基金青年科学基金(批准号:11504294)、国家自然科学基金面上项目(批准号:61378083)、国家自然科学基金重大研究计划培育项目(批准号:91123030)、科技部中美合作项目(批准号:2011DFA12220)、陕西省自然科学基础研究计划青年人才项目(批准号:2016JQ1030)和陕西省自然科学基金(批准号:14JS106,2013SZS03-Z01)资助的课题. （Grant No.11504294）
