中文摘要：

提出了一种定量测量光纤内部折射率三维分布的新方法。基于数字全息显微断层成像技术，构建了一套测量光纤折射率的实验系统，实现了光纤内部折射率分布的三维测量。在预放大透射式数字全息显微系统中，加入样品转动装置，利用样品转动记录180°视角内各个角度的显微全息图，然后数值计算出每个角度光纤样品的折射率积分投影，并基于滤波反投影算法重建光纤内部折射率的三维分布。普通单模光纤和熊猫型保偏光纤两组样品的实验结果表明：建立的系统可应用于光纤内部折射率三维分布定量测量。

英文摘要：

A new method to measure the three-dimensional refractive index distribution of optical fiber is proposed. A set of experiment system based on microscopic tomography with sample rotation is set up, which can quantitatively reconstruct the three-dimensional refractive index distribution inside optical fiber. The digital holograms are acquired at regularly-spaced angular positions within 180° viewing angle by the rotating sample in the digital holographic microscopy system of pre-amplification transmission type. Then, the refractive index integral projections for each degree＇s optical fiber sample is calculated from the holograms. The three-dimensional refractive index distribution of the internal optical fiber is rebuilt by filtered back-projection algorithm. The experimental results of single-mode optical fiber and single-mode polarization maintaining optical fiber with the panda type demonstrate that the established system is feasible and effective in measuring the three-dimensional refractive index distribution of optical fiber.