Large-FOV high-resolution micro-CT via cascaded fiber tapers

Micro-CT imaging is widely used in materials science, biomedical research, geological exploration, and industrial inspection due to its non-destructive capabilities. However, traditional systems face challenges due to limitations in spatial bandwidth product (SBP), making it difficult to achieve both a large field-of-view (FOV) and high-resolution imaging simultaneously. This paper presents a segmented light deflection method using cascaded optical fiber tapers integrated within a "fiber taper-image intensifier-camera" coupling architecture. This design reduces distortion caused by large taper ratios in single-stage systems. Additionally, a multi-view geometric registration calibration approach is developed based on CT projection geometric constraints to address mismatches between traditional 2D planar distortion correction methods and CT projection geometry. A cascaded fiber taper array (53 mm input - 34 mm intermediate - 16 mm output) was implemented in a 2 × 2 tiling configuration. The system achieves wide-FOV micro-CT imaging with a maximum imaging area of 106.4 × 106.4 mm². Resolution testing confirmed a 3 μm resolution within a 4.1 × 4.1 mm² FOV. System reconstruction efficacy was validated through rock core and printed circuit board (PCB) samples.