Preform index profiling (PIP).
Preform index profiling (PIP).
复制标题
预制件指数分析 (PIP)。
作者：
H. Presby;D. Marcuse
提出了一种自动无损聚焦测量光纤预制棒折射率分布的方法。预制件浸入折射率匹配油中，准直光横向穿过预制件。透射光的强度分布是用配备在核心边界外的低f数透镜的摄像机来检测的。光线分布的记录和处理在计算机控制的视频分析系统的帮助下进行。根据光强分布计算出预制棒的折射率分布，绘制并在几分钟内用幂函数曲线进行拟合。折射率测量的重复性好于1%，并与用相同预制棒尖端的板材样品干涉测定的轮廓获得了很好的一致。
An automatic and nondestructive focusing method to determine the refractive index distributions of optical fiber preforms is presented. The preform is immersed in index matching oil, and collimated light is passed transversely through it. The intensity distribution of the transmitted light is detected with a vidicon camera equipped with a low f-number lens focused just outside the core boundary. Recording and processing of the light distribution follow with the aid of a computer-controlled video-analysis system. The refractive index profile of the preform is computed from the intensity distribution, plotted, and fitted with a power-law curve within several minutes time. The repeatability of the index measurement is better than 1%, and excellent agreement is obtained with profiles determined interferometrically using slab samples from the tips of the same preforms.