镀金属四包层长周期光纤光栅特征方程的建立与求解  

Establishment and solution of the characteristic equation of metal-coated quadruple clad long-period fiber grating

作　　者：徐艳平[1] 顾铮■ 陈家璧[2] 

机构地区：[1]上海第二工业大学电子与电气工程学院,上海201209 [2]上海理工大学光学与电子信息工程学院,上海200093

出　　处：《上海理工大学学报》2006年第1期9-13,共5页Journal of University of Shanghai For Science and Technology

基　　金：上海市教委曙光计划资助项目(02SG32);上海市自然科学基金资助项目(03ZR14071);上海市重点学科建设资助项目(T0501)

摘　　要：根据耦合模理论,建立了镀金属四包层长周期光纤光栅气体传感器的模型和特征方程,讨论了由于金属的复折射率虚部较大,引起特征方程中贝塞尔函数溢出的问题.提出了采用在贝塞尔函数源程序中乘上一个缩放因子解决溢出问题的方法,并给出了3种解决办法———积分法、幂级数法和渐进展开法.Based on coupled-mode theory, the general model and characteristic euqation of metal-coated quadruple clad long-period fiber grating gas sensors are established. The problem of overflow of the Bessel functions caused by the big imaginary part of the complex refractive index of metal is discussed detailedly. The solution is given by a programmed scaling of each step of the calculation of the Bessel functions. In addition, three procedures （the integral method, the power series, and the asympotic expansion） are discussed detailedly.

关 键 词：长周期光纤光栅 金属包层 复折射率 复特征方程 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]