Volume 15 Issue 6
Dec.  2022
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XIN Tao, PENG Shuo, DONG Li-quan, ZHANG Shao-hui, ZHANG Cun-lin. Improving terahertz imaging by light field processing[J]. Chinese Optics, 2022, 15(6): 1313-1320. doi: 10.37188/CO.EN.2022-0005
Citation: XIN Tao, PENG Shuo, DONG Li-quan, ZHANG Shao-hui, ZHANG Cun-lin. Improving terahertz imaging by light field processing[J]. Chinese Optics, 2022, 15(6): 1313-1320. doi: 10.37188/CO.EN.2022-0005

Improving terahertz imaging by light field processing

doi: 10.37188/CO.EN.2022-0005
Funds:  Supported by Founding of National Key Research and Development Program of China (No. 2021YFC2202400); Foundation Enhancement Program (No. 2021-JCJQ-JJ-0823); National Natural Science Foundation of China (No. 61735003)
More Information
  • Author Bio:

    XIN Tao (1971—), male, was born in Shi jia Zhuang, Hebei province. He received his bachelor's degree from Hebei University of Mechanical and Electrical Engineering in 1995 and his master's degree from Yanshan University in 2004. He now works at the Vocational and Technical College of Hebei Normal University. His research interests include terahertz imaging and computer graphics problems, particularly the optimization of terahertz images using light field techniques. E-mail: xintao71@mail.hebtu.edu.cn

    PENG Shuo (1995—), female, was born in ShijiaZhuang. Hebei province. She received the B.Eng degree from Beijing Institute of Technology in 2017 and is currently working toward the D.Eng degree at School of Optics and Photonics, BIT. Her research interests include light-field imaging and 3D measurement. E-mail: pengshuoeve@163.com

  • Corresponding author: zhangshaohui@bit.edu.cncunlin_zhang@cnu.edu.cn
  • Received Date: 31 Mar 2022
  • Accepted Date: 13 May 2022
  • Rev Recd Date: 21 Apr 2022
  • Available Online: 10 Jun 2022
  • Terahertz (THz) technology becomes increasingly important nowadays, especially in testing and security applications. Extending the field of view and increasing the imaging quality are both vital challenges for THz imaging. To address these problems, we build a THz light field imaging system based on a single-camera scanning configuration, which utilizes the 4D information of the spatial and angular distribution of THz waves. Based on the 4D plenoptic function and the parameterization method with two parallel planes, the intensity consistency of THz propagation is used for refocusing calculation, then a series of refocused images can be obtained by integrating original light field images corresponding to different imaging distances and views. Compared with the original THz imaging, the field of view and the imaging quality of the THz light field imaging are effectively improved. In our experiment, the field of view was enlarged by a factor of 1.84 and the resolution increased from 1.3 mm to 0.7 mm. Furthermore, information on some obscured targets could also be retrieved by defocusing the obstructions. This method could improve the imaging quality of THz imaging as well as expand its functions, which inspires a new way for THz nondestructive testing (NDT) and security inspection.


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