Fig. 1. Optical fiber refractive index measurement of micro tomography based on unit interference

Fig. 2. Simulation projection integrals of single-mode fiber, multi-mode fiber, panda-type polarization-maintaining fiber and grapefruit-type photonic crystal fiber at θ=0^o, 22.5^o, 45^o, 90^o

Fig. 3. Sinograms of single-mode fiber, multi-mode fiber, panda-type PM fiber, and grapefruit-type photonic crystal fiber at different numbers of projections and angles

Fig. 4. Refractive index distribution of the fiber according to the back-projection of the sinogram in Fig. 3

Fig. 5. Interferogram, phase distribution 3D display of single-mode and multi-mode fibers

Fig. 6. Refractive index distribution of the single-mode fiber and multi-mode fiber along the diameter direction and cross-section of the fault plane