【作者】 周鸿颖； 陈家璧； 邱高；

【Author】 ZHOU Hongying a, b CHEN Jiabu a and QIU Gaob aDonghua University, College of Basic Sciences ,shanghai, bUniversity of Shanghai for Science and Technology, College of Opticals and Electronics

【机构】 东华大学理学院； 上海理工大学光电学院；

【摘要】 聚合物光纤预制棒的折射率决定了光纤的传输特性,目前较为常用的几种测量方法主要有干涉测量法、近场扫描法和聚焦法。本文主要研究了一种新的测量方法——细光束扫描来测量光线预制棒的折射率分布。细光束照射到预制棒上,预制棒就像是柱透镜使光线会聚,光线在预制棒中经过一系列的折射后,从另一端出射出来。在假定预制棒内折射率分布的基础上,应用几何光学中的折射定律对扫描光线进行追迹,计算其在预制棒内的传播路径,最后得到理论上出射的位置,而通过测量可以得到实际光线出射的位置,利用这两个结果的差异构造评价函数,运用蒙特卡罗算法对假定的折射率分布进行反复的修正,直到最后评价函数趋向于一个很小的值,此时折射率分布也趋向于其真实分布,达到测量的目的。更多还原

【Abstract】 The distributing of refraction ratio of section plane of polymer optical fiber come to a decision the transfer characteristic of polymer optical fiber. Now the primarily measure methods of in common use are interferometer method, neat-field scan, focusing method. In this paper a new measure method is described--- the technique of thin beam scan to measure the distributing of refraction ratio of section plane of polymer optical fiber. When thin beam irradiated section plane of polymer optical fiber, the light is converged because of the section plane of polymer optical fiber like columnar lens. After pass by a series of refract empress inside section plane of polymer optical fiber, the light pass through section plane of polymer optical fiber and out of the other side. First we supposition the distributing of refraction ratio of section plane of polymer optical fiber, second we calculate the contrail of thin beam with refraction law in geometrical optics based on the supposition, last we get light dipping location of theoretic. At the same time we get the light dipping location of practicality by experiment. We can construct a evaluation function with difference of two result. And correct the supposition of the distributing of refraction ratio of section plane of polymer optical fiber by Monte-Carlo method time after time. At last the evaluation function value will get very little and we get the distributing of refraction ratio of section plane of polymer optical fiber.更多还原