Imaging Science and Photochemistry ›› 2020, Vol. 38 ›› Issue (2): 181-189.DOI: 10.7517/issn.1674-0475.191001

• Review and Articles • Previous Articles     Next Articles

Research on Multi-diffraction Phase Imaging Restricted by Large Numerical Aperture Optical Lens

WANG Qian1,2, CHEN Xin1,2, WEN Yongfu1,2, YANG Hao1, WANG Huaying3, CHENG Haobo1,2   

  1. 1. Shenzhen Research Institute, Beijing Institute of Technology, Shenzhen 518057, Guangdong, P. R. China;
    2. School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, P. R. China;
    3. School of Mathematics and Physics, Hebei University of Engineering, Handan 056038, Hebei, P. R. China
  • Received:2019-10-14 Online:2020-03-15 Published:2020-03-15

Abstract: Digital holographic microscopy imaging technology is a quantitative phase imaging technology combined with digital holography technology and traditional optical microscopy imaging technology. Owing to there are speckles and parasitic stripe noise in traditional laser off-axis holographic microscopy imaging system and the traditional off-axis digital holographic microscopy of partial coherent light illumination has the problem of poor contrast of coherent fringes, the diffraction phase microscopy imaging system with monochromatic LED illumination is putted forward in this paper. Grating is used to obtain multi-level diffraction of object light. And 0th and +1st order light are separated by 4f system and spatial filter, which are used as reference light and signal light, respectively. Two beams interfere with each other on the CCD and generate off-axis hologram. Thereby a common-path and off-axis holographic imaging structure is formed. Through theoretical analysis and calculation, the optical components used in the experiment are picked to guarantee that the diffracted light spectrum information can be separated and accord with the sampling conditions. In conclusion, the experimental results demonstrate that the proposed system can derive higher imaging accuracy and signal-to-noise ratio than the traditional laser off-axis digital holographic microscopy imaging results.

Key words: digital holography, quantitative imaging, diffraction grating, NA, common-path and off-axis