Shibata N, Kawachi M, Edahiro T
NTT Public Corporation, Ibaraki Electrical Communication Laboratory, Tokai, Ibaraki-ken 319-11, Japan.
Appl Opt. 1982 Oct 1;21(19):3507-10. doi: 10.1364/AO.21.003507.
An automatic and nondestructive method for measuring the refractive-index profile of optical fiber preforms using the photoelastic effect is presented. The method is applied to single-mode fiber preforms fabricated by the VAD technique. A collimated beam of linearly polarized light is passed transversely through the preform. The transmitted light is detected with a video camera equiped with a large diameter lens, a quarter-wave plate, and an analyzer. The refractive-index profile is computed from the light intensity distribution. Excellent agreement is obtained with core diameters and profiles determined from interference microscopic observation on preform slab samples.
提出了一种利用光弹效应测量光纤预制棒折射率分布的自动无损方法。该方法应用于采用VAD技术制造的单模光纤预制棒。一束准直的线偏振光横向穿过预制棒。透过的光由配备大直径透镜、四分之一波片和检偏器的摄像机进行检测。根据光强分布计算折射率分布。与通过预制棒平板样品的干涉显微镜观察确定的纤芯直径和分布取得了极好的一致性。
