为了提高太赫兹相干层析成像系统的纵向分辨率, 采用色散补偿方法解决了宽带光源做成像光源带来的色散问题。基于评价函数的迭代补偿算法对降噪滤波后的原始信号进行色散补偿, 得到了较为清晰的3维重构图像。结果表明, 在迭代补偿算法的计算中, 无需预知样品的厚度信息以及色散特性, 即可获得高精度的3维重构图像, 纵向分辨率高达100μm。该研究在高精度的材料无损探测领域具有较大的研究价值和广泛的应用前景。

In order to improve the longitudinal resolution of a terahertz coherence tomographic imaging system, the dispersion compensation method was used to solve the dispersion problem caused by the broadband light source. The iterative compensation algorithm based on the evaluation function was used to compensate the dispersion of the original signal after noise reduction, and clear 3-D reconstructed images were obtained. The results show that 3-D high precision reconstruction images can be obtained without predicting the thickness information and dispersion characteristics of the sample. The longitudinal resolution is up to 100μm. This research has great research value and wide application prospect in the field of high precision nondestructive detection.