3D refractive index measurements of special optical fibers

作者：Yan Cheng; Huang Su-Juan^*; Miao Zhuang; Chang Zheng; Zeng Jun-Zhang; Wang Ting-Yun

来源：Optical Fiber Technology, 2016, 31: 65-73.

DOI：10.1016/j.yofte.2016.05.007

• Digital holography
• Phase distribution
• 3D refractive index
• Special optical fiber
• Filtered back projection algorithm

A digital holographic microscopic chromatography-based approach with considerably improved accuracy, simplified configuration and performance stability is proposed to measure three dimensional refractive index of special optical fibers. Based on the approach, a measurement system is established incorporating a modified Mach-Zehnder interferometer and lab-developed supporting software for data processing. In the system, a phase projection distribution of an optical fiber is utilized to obtain an optimal digital hologram recorded by a CCD, and then an angular spectrum theory-based algorithm is adopted to extract the phase distribution information of an object wave. The rotation of the optic fiber enables the experimental measurements of multi-angle phase information. Based on the filtered back projection algorithm, a 3D refraction index of the optical fiber is thus obtained at high accuracy. To evaluate the proposed approach, both PANDA fibers and special elliptical optical fiber are considered in the system. The results measured in PANDA fibers agree well with those measured using S14 Refractive Index Profiler, which is, however, not suitable for measuring the property of a special elliptical fiber.

• 出版日期2016-9
• 单位上海大学