Xu Kuangyi, Harris Zachery B, Vahey Paul, Arbab M Hassan
Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.
Boeing Research & Technology, Seattle, WA 98108, USA.
Sensors (Basel). 2024 Nov 22;24(23):7467. doi: 10.3390/s24237467.
Recent advancements in novel fiber-coupled and portable terahertz (THz) spectroscopic imaging technology have accelerated applications in nondestructive testing (NDT). Although the polarization information of THz waves can play a critical role in material characterization, there are few demonstrations of polarization-resolved THz imaging as an NDT modality due to the deficiency of such polarimetric imaging devices. In this paper, we have inspected industrial carbon fiber composites using a portable and handheld imaging scanner in which the THz polarizations of two orthogonal channels are simultaneously captured by two photoconductive antennas. We observed significant polarimetric differences between the two-channel images of the same sample and the resulting THz Stokes vectors, which are attributed to the anisotropic conductivity of carbon fiber composites. Using both polarimetric channels, we can visualize the superficial and underlying interfaces of the first laminate. These results pave the way for the future applications of THz polarimetry to the assessment of coatings or surface quality on carbon fiber-reinforced substrates.
新型光纤耦合便携式太赫兹（THz）光谱成像技术的最新进展加速了其在无损检测（NDT）中的应用。尽管太赫兹波的偏振信息在材料表征中可发挥关键作用，但由于此类偏振成像设备的不足，很少有将偏振分辨太赫兹成像作为一种无损检测方式的实例。在本文中，我们使用了一种便携式手持式成像扫描仪对工业碳纤维复合材料进行检测，其中两个正交通道的太赫兹偏振由两个光电导天线同时捕获。我们观察到同一样品的双通道图像以及所得太赫兹斯托克斯矢量之间存在显著的偏振差异，这归因于碳纤维复合材料的各向异性电导率。利用两个偏振通道，我们可以可视化第一层压板的表面和底层界面。这些结果为太赫兹偏振测量在评估碳纤维增强基材上的涂层或表面质量方面的未来应用铺平了道路。
