太赫兹成像是太赫兹技术的重要发展方向，其中具备实时成像能力的面阵成像系统引起了广泛的研究兴趣。在成像系统的设计中需要尽可能地减小能量损耗，由于离轴抛物面镜具有较小的能量损耗，且便于系统设计，因此在太赫兹成像系统的设计中常被用到。但离轴抛物面镜的引入会带来一定的畸变以及装调困难。利用光学设计软件ZEMAX，对一种具有离轴抛物面镜的太赫兹面阵成像系统进行了成像性能分析，特别研究了接收部分中离轴抛物面镜装调误差对成像质量的影响。仿真结果表明，理想情况下，系统分辨率约为0.5 mm且网格畸变只有0.069%；该系统容许光学接收部分的离轴抛物面镜最大倾斜角1.1°，最大偏心距6.5 mm。

Nowadays, terahertz(THz) imaging is an important research focus among the development of THz techniques. And imaging systems based on array detectors which have real time imaging capability have attracted lots of research interests. It is essential to reduce power losses during the system design. Owing to the low energy losses and design convenience it brings, off-axis parabolic mirrors have been frequently used in many THz imaging systems. A 2D THz array imaging system comprised of off-axis parabolic mirrors is analyzed using an optical design software ZEMAX. The deterioration of the image quality caused by the misalignment of off-axis parabolic mirror in the receiving part is investigated. The simulation results show that the image resolution can reach 0.5 mm for the ideal case, and the grid distortion is 0.069%. The system has a tolerance of 1.1° for the misalignment angle of the off-axis parabolic mirror. The tolerance for the decenter error is 6.5 mm.