X射线硬化是导致工业CT重建图像质量下降的物理原因之一。硬化伪影通常表现为两种形式, 即杯状伪影和带状伪影。描述并证实了硬化伪影的一种新型表现形式, 这种伪影与真实结构相关, 且分布规则, 容易造成伪影与真实结构的混淆。采用线性化校正方法对该伪影进行抑制, 提高了重建图像质量, 改善了通过CT重建图像进行几何测量的精度。

The depth ranges of typical implementations of Fourier domain optical coherence tomography (FDOCT), including spectral domain OCT (SDOCT) and swept source OCT (SSOCT), are limited to several millimeters. To extend the depth range of current OCT systems, two novel systems with ultralong depth range were developed in this study. One is the orthogonal dispersive SDOCT (OD-SDOCT), and the other is the recirculated swept source (R-SS) interferometer/OCT. No compromise between depth range and depth resolution is required in both systems. The developed OD-SDOCT system realized the longest depth range (over 100 mm) ever achieved by SDOCT, which is ready to be modified for depth-encoded parallel imaging on multiple sites. The developed R-SS interferometer achieved submicron precision within a depth range of 30 mm, holding potential in real-time contact-free on-axis metrology of complex optical systems.