为获得太赫兹波对常见衣物布料的穿透特性, 基于布料的物理结构以及太赫兹波传输的影响因素, 建立了常见布料的太赫兹波传输模型, 计算获得了不同相对湿度条件下典型太赫兹波长对布料的透过率。随后, 利用太赫兹时域光谱系统对棉质布料样品进行透射实验测试, 获得了布料在0.1~2 THz范围内不同相对湿度条件下的透过率。通过理论计算结果与实验测试结果的对比分析, 验证了该传输模型的有效性, 获得了太赫兹波对常见棉质布料的穿透特性。此外, 在30%相对湿度条件下, 实验研究了多层棉质布料的太赫兹透射特性。研究结果表明, 在可见光波段“不透明”的衣物布料, 利用太赫兹波可实现良好的“透视”, 但其对布料的穿透特性一定程度上受到环境相对湿度的影响, 该研究对于衣物内隐藏危险物品的快速检测具有重要意义。

In order to acquire penetrability of terahertz (THz) for common fabric, transmission model of fabric at THz frequency was built and described, which was based on physical structure of it and various influencing factors on THz transmission in atmosphere, to calculate the transmittance of fabric at THz on different relative humidity (RH) levels. Then, transmission experiment about cotton sample on different RHs was conducted by using terahertz time-domain spectroscopy to obtain the transmittance of sample at 0.1－2 THz. The effectiveness and veracity of the model were verified by comparing the results of theoretical calculation and experiment. And transmission characteristic of THz for cotton fabric at different environmental conditions was obtained. In addition, transmission experiment of THz for multilayers fabric was conducted on 30%RH. The results show that the fabrics, which are opaque in visible region, are almost transparent in terahertz region. But the transmission characteristic is partly influenced by environmental RH. Therefore, this research is of significance in rapid detection and identification of concealed danger in cloth.