Refractive index (RI) is a fundamental parameter of optical material, and RI spectrum (RIS) is essential for many fields. Current RI measurement is only for some discrete spectral lines, and has extremely high requirements on measurement operation and accuracy. A measurement method of continuous RIS distribution in a wide spectral range was proposed in this work. A swept-source optical coherence tomography using a Mach-Zehnder configuration was used to detect interference spectrum signal, which phase was obtained by using Hilbert transform. By detecting the sample-induced phase and using the proposed equations, RIS of a sample could be obtained. Five measurements on the RIS distributions of two optical materials were conducted for a spectral range of 90 nm, and the results were in agreement with the theoretical distributions, verifying the method's validity. Its principle and operation are simple, and system has the potential to be miniaturized, making it possible to become a useful tool for RIS measurement, especially in some special occasions.

折射率（RI）是光学材料的基本参数，折射率光谱（RIS）在很多领域都是必不可少的。目前的RI测量只是针对一些离散的谱线，对测量操作和精度要求极高。本文提出了一种在宽光谱范围内连续 RIS 分布的测量方法。使用 Mach-Zehnder 配置的扫频源光学相干断层扫描用于检测干涉光谱信号，其相位是通过使用希尔伯特变换获得的。通过检测样品诱导相位并使用所提出的方程，可以获得样品的 RIS。在90 nm的光谱范围内对两种光学材料的RIS分布进行了五次测量，结果与理论分布一致，验证方法的有效性。它的原理和操作简单，系统具有小型化的潜力，有可能成为RIS测量的有用工具，特别是在一些特殊场合。