Shen Sishi, Hao Congjing, Liang Bin, Liu Jinsong, Yang Zhengang, Wang Kejia
Opt Lett. 2024 May 1;49(9):2481-2484. doi: 10.1364/OL.523116.
A terahertz (THz) fan-beam computed tomography (CT) system using a 0.3 THz continuous-wave sheet beam is proposed. The diffraction-free sheet beam expands in a fan shape in only one direction and provides propagation-invariant focal lines and extended the depth-of-field. The fan-beam CT based on this beam is the second-generation THz CT. It breaks the conventional 4-f symmetric structure of THz CT using the parallel beam. The fan-beam THz CT allows for use with a linear array detector, which reduces the time required to collect data. To demonstrate its feasibility for three-dimensional (3D) imaging, the 3D structure of a metal rod packed in a carton is reconstructed with the support of the system. The results show that the object's internal structure can be obtained by this new THz CT system while retaining the geometrically magnified features of the cross-sectional structure. The results of our research provide a template for the second-generation THz CT system, which provides an additional method for nondestructive testing.
提出了一种使用0.3太赫兹连续波片状光束的太赫兹（THz）扇束计算机断层扫描（CT）系统。无衍射片状光束仅在一个方向上呈扇形扩展，并提供传播不变的焦线并扩展景深。基于此光束的扇束CT是第二代太赫兹CT。它打破了使用平行光束的太赫兹CT的传统4-f对称结构。扇束太赫兹CT允许使用线性阵列探测器，这减少了收集数据所需的时间。为了证明其用于三维（3D）成像的可行性，在该系统的支持下重建了包装在纸箱中的金属棒的3D结构。结果表明，通过这种新型太赫兹CT系统可以获得物体的内部结构，同时保留横截面结构的几何放大特征。我们的研究结果为第二代太赫兹CT系统提供了一个模板，该系统为无损检测提供了一种额外的方法。
