太赫兹波能穿透很多不透明的非金属材料（如部分复合材料，陶瓷材料等），利用它能直接探测这些材料内部的信息。本项目旨在通过建立考虑色散的各向异性应力光学效应表征模型，综合利用太赫兹时域光谱（THz-TDS）成像和太赫兹偏振态感知两项关键技术实现对不透明材料二维应力场的测量。重点研究该方法的测试原理及技术，并建立相应的快速高分辨应力场测试系统。拟重点解决以下四方面的问题： 1）研究应力光学效应的色散现象及其表征模型，2）研究各向异性应力光学效应系数的测定方法；3）建立基于单脉冲展宽和近场扫描的THz-TDS系统，实现亚波长分辨率太赫兹光谱图像的快速采集；4）建立适用于THz-TDS系统的应力传感光路，并开发相应的应力提取算法。最后，综合利用上述技术，建立快速高分辨的不透明材料二维应力场测量系统，发展成为一种全新的应力场测量技术。

Terahertz (THz) electromagnetic wave can penetrate many optically opaque materials (for example some composites and ceramics), so that it can be used to obtain information in these materials. In this project, a new 2D stress field measurement technique is proposed by combining THz-TDS imaging and THz polarization state detection technology. The main focuses of this projection are to research the principles of stress measurement by terahertz wave, and establish the stress measurement system with high resolution and speed. Problems regarding the following four aspects are discussed. First, an effective model will be developed to descript the dispersion of stress-optical effect. Secondly, the effective technique will be established to determine the coefficients of anisotropic stress-optical effect. Thirdly, a sensitive THz spectrum imaging system will be established by introducing single-pulse chirped amplification and near-field scanning technology. Fourthly, an stress-sensing optical path will be developed in THz-TDS system, and the algorithm for stress determination will be established. Finally, the previously mentioned techniques will combined to establish a stress field measurement system for optically opaque materials with high resolution and speed. This technique will be a promising method for stress measurement for opaque materials.