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太赫兹(THz)波检测是一种新型有效的相干检测方法,它可以同时获得被检测物质的振幅和相位信息。利用太赫兹时域光谱技术(THz-TDS)对几种常见水进行了测谱分析;采取迭代的方法,消除了吸收近似带来的误差,完善了透射式太赫兹时域光谱技术中传统的数据处理方法;通过比较不同的滤波器,确定了Symlets9小波滤波为最优的滤波方式;拟合得到了折射率和吸收系数随频率指数变化的规律,其相关系数的平方达到0.9以上。结果表明,不同水的折射率和吸收系数变化曲线的参数值的差异和拟合相关性的不同,可以作为区分水质好坏的依据。
THz wave detection is a new and effective coherent detection method, which can simultaneously obtain the amplitude and phase information of the tested substances. The terahertz time-domain spectroscopy (THz-TDS) was used to conduct the spectrometric analysis of several common water. By adopting an iterative method, the error caused by the absorption approximation was eliminated, and the traditional method of transmitting terahertz time-domain spectroscopy Data processing method. By comparing different filters, the filtering method of Symlets9 wavelet filter is determined to be the optimal filtering method. The law of the refractive index and absorption coefficient with the frequency index is fitted and the square of the correlation coefficient reaches above 0.9. The results show that the difference between the refractive index and absorption coefficient curves of different water and the fitting correlation can be used as the basis for distinguishing water quality from water quality.