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。 A new method for quantitatively measuring the three-dimensional distribution of refractive index in fiber is proposed. Based on digital holographic microscopic tomography, a set of experimental system for measuring the refractive index of optical fiber was constructed, which realized the three-dimensional measurement of refractive index distribution in optical fiber. In the pre-transmission digital holographic microscopy system, a sample rotating device is added. The sample is rotated to record the micro-holograms at various angles within a 180 ° viewing angle. The integral refractive index refraction projections of the fiber samples at each angle are numerically calculated and calculated based on Reconstruction of Three - Dimensional Distribution of Internal Refractive Index in Optical Fiber by Back - Projection Algorithm. The experimental results of two samples of ordinary single-mode fiber and panda-type polarization maintaining fiber show that the system can be applied to the quantitative measurement of three-dimensional distribution of refractive index in fiber.