Suppression of Cladding Mode Coupling by B/Ge Codoped Photosensitive Fiber With Photosensitive and Depressed Inner Cladding

Excess loss on the short wavelength side of the Bragg resonant wavelength caused by cladding mode coupling limits wide use of grating in the fiber communication system, especially in densed wavelength division multiplexing (DWDM) system. A novel photosensitive fiber design that have depressed cladding and photosensitive inner cladding in the same fiber is proposed, which can suppress cladding mode coupling greatly. Using MCVD method B/Ge codoped fiber with depressed cladding was fabriceted out, which was also doped in boron and germanium and had the photosensitivity. Finally, the transmission spectrum of written grating in this fiber by phase mask method verified its larger photosensitivity and greatly suppression of cladding mode coupling.

紫外写入光纤光栅用特种光纤的研究

本文详细地介绍了如何加强用于制做紫外写入光纤光栅所需的特种光纤的高光敏性、温度不敏感性以及对包层模的高度抑制性等。

具有光敏下陷包层的B/Ge共掺光敏光纤的研制

紫外光纤光栅的包层模造成的损耗限制了光栅在波分复用系统中的使用。文章分析了同时具有下陷内包层和光敏内包层的光敏光纤可以极大地抑制包层模耦合，并采用 ＭＣＶＤ工艺制作出了硼和锗共掺（Ｂ／Ｇｅ）的带光敏的下陷内包层的光纤，经写入紫外光纤光栅证实该光敏光纤确实极大地抑制了包层模耦合。

用于紫外写入光纤光栅的特种光纤的研究

本文详细地介绍了一些适合于紫外写入光纤光栅的特种光纤，如高光敏性光纤、温度不敏感性光纤以及能抑制包层模的特种光纤。

基于离轴刻写的FBG包层模式的光纤弯曲传感器

基于光纤光栅(FBG)包层模式,制作了一种弯曲在线监测的全光纤传感器。传感器使用193nm ArF准分子激光器,通过离轴刻栅的方式在15mm单模光纤上刻写的光栅。对该传感器的弯曲和温度变化的响应特性进行了理论分析,并在0~1.2m-1曲率变化范围内,对传感器的弯曲响应特性进行了实验研究,结果表明,随着弯曲曲率的增大,包层模式的强度下降。其对弯曲的响应灵敏度为0.11dB/m-1,线性度为0.996,表现出了它较高的灵敏度和线性度。随着环境温度从25℃变化到60℃,该传感器峰值波长响应灵敏度为0.02nm/℃。结果表明,该型传感器对温度干扰不敏感。由于其结构简单,制作方便,精度高,在油气田管道健康监测领域有较好的应用前景。