利用太赫兹时域光谱技术检测水和氯化钠溶液

太赫兹电磁波谱与液体分子的转动和振动能量对应，适合研究液体分子的动力学信息。水和氯化钠广泛存在于生物组织中，也是生命的重要组成部分。太赫兹时域光谱技术被广泛应用于液体检测，通过分析溶液中物质内部结构以及分子微观运动状态，在0.2~1.5 THz频率下，可以得到物质的吸收系数、折射率以及介电函数等。利用德拜模型模拟实验结果得到水溶液、氯化钠溶液的介电函数以及弛豫时间，可得到水和氯化钠溶液分子快速移动的特征时间分别为9.6 ps和10.7 ps，并获得了与分子结构相关的动力学信息。

Detection of NaCl solutions using terahertz time-domain spectroscopy

Terahertz spectrum is corresponding with vibration and rotation of liquid molecules. It is suitable to identify and research the liquid molecular dynamics. As a powerful spectral detection technology, Terahertz Time-Domain Spectroscopy(THz-TDS) is widely applied in solution detection. The absorption coefficient, refractive index and dielectric function of solutions can be extracted based on terahertz time-domain spectroscopy. Water and NaCl exist in most biological tissues, which are very important for life. In this paper, water and NaCl solutions are detected under room temperature by THz-TDS technique in the range of 0.2-1.5 THz. The terahertz dielectric function of the water and NaCl (sodium chloride) solutions is fitted by Debye model, from which the dielectric relaxation time can be obtained. By means of dielectric relaxation process, it is found that the characteristic time of molecular movement and the information related to the liquid molecular structure and movement are obtained. The terahertz dielectric function of the water and NaCl solutions is fitted by Debye model, where the dielectric relaxation time of water and NaCl solutions is 9.6 ps and 10.7 ps respectively. By means of dielectric relaxation process, it is found that the characteristic time of molecular movement and the information related to the liquid molecular structure and movement are obtained.