被动太赫兹成像二维扫描技术

摘要

It is inevitable to use 2-D scanning in wide-Field of View(FOV) terahertz imaging due to the restriction of terahertz detector(lack of pixels and hardly integrated to large-scale plane array). The 45° mirror could be used in passive terahertz 2-D scanning imaging for its advantages in dimension, stability and scanning Field of View. The principle of 2-D scanning imaging using 45° mirror is analyzed in detail. A new method with horizontal scanning by rotating around axis Zand vertical stepping by rotating around axis Yis proposed. The scanning trace is calculated, the margin FOV distortion is about 3.2%. The method is validated by the imaging experiment and image is acquired in wide-Field of View.%太赫兹成像受探测器像元数少和无法进行大规模面阵集成的限制，大视场成像不可避免地要用到二维扫描。45º镜具有尺寸小，稳定性好，幅宽大等特点，可以用来实现被动太赫兹二维扫描成像。详细分析了45º镜扫描成像的工作原理和扫描方式，提出了绕Z轴摆动实现水平扫描，绕Y轴摆动实现垂直步进的扫描方案，计算了扫描轨迹，边沿视场成像畸变约3.2%，并通过成像实验对扫描方案进行了验证，得到了大视场下的被动太赫兹二维扫描图像。