摘要
在数字全息粒子场成像中,粒子衍射的孔径角很小,重构时具有很长的焦深,造成轴向定位精度远低于横向定位精度。增大照明波长,相当于增大粒子孔径角,因此可得到更高的轴向定位精度。采用红外相干光源照明粒子场,在不提升算法和系统复杂度的前提下提升数字全息粒子场重构的轴向定位精度。从理论上分析数字全息粒子场重构中焦深与轴向定位精度的关系,并分别仿真分析绿光、红光及红外光照明时的粒子场全息重构,分别开展了基于这3种光源的聚苯乙烯微球粒子场全息成像实验。仿真和实验结果研究表明,相比红光,红外光源使焦深减小了约19%,而相比绿光,焦深减小了约39%。增加波长可以减弱离焦像的层间干扰,从而提高了轴向定位精度。
In digital holographic particle field imaging,the small aperture angle of particle diffraction results in an increased depth of focus during reconstruction.This leads to a significantly lower axial positioning accuracy compared with lateral positioning accuracy.Therefore,higher axial positioning accuracy can be achieved by increasing the illumination wavelength,which is equivalent to increasing the particle aperture angle.This study proposes the use of infrared coherent light source to illuminate the particle field to improve the axial positioning accuracy of digital holographic particle field reconstruction without increasing the complexity of algorithms and systems.This study theoretically analyzes the relationship between focal depth and axial positioning accuracy in digital holographic particle field reconstruction.Simulation and analysis of holographic particle field reconstruction are conducted under green,red,and infrared light illumination.Moreover,holographic imaging experiments of polystyrene microsphere particle field based on these three light sources are performed.The simulation and experimental results show that compared with red and green lights,the infrared light source reduces the focal depth by approximately 19% and 39%,respectively.Also,increasing the wavelength weakens the interlayer interference of defocused images,thereby improving axial positioning accuracy.
作者
苏萍
周柏臻
郝治涛
马建设
任振波
Su Ping;Zhou Bozhen;Hao Zhitao;Ma Jianshe;Ren Zhenbo(Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,Guangdong,China;School of Physical Science and Technology,Northwestern Polytechnical University,Xi’an 710072,Shaanxi,China;Shenzhen Research Institute,Northwestern Polytechnical University,Shenzhen 518063,Guangdong,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2024年第2期329-335,共7页
Laser & Optoelectronics Progress
基金
国家自然科学基金(62275218)
中国博士后科学基金(2022M712586)
广东省基础与应用基础研究基金(2023A1515011335)
中央高校基本科研业务费(D5000230117)。
关键词
数字全息
粒子场
红外光
轴向定位精度
digital holography
particle field
infrared light
axial positioning accuracy
