椭圆芯双模光纤特性的理论研究及应用  

Research and Application of Elliptical Core Dual-Mode Fiber

作　　者：王河林[1] 杨爱军[1] 郑绳楦[1] 

机构地区：[1]燕山大学信息科学与工程学院,河北秦皇岛066004

出　　处：《光纤与电缆及其应用技术》2006年第5期1-4,9,共5页Optical Fiber & Electric Cable and Their Applications

基　　金：国家自然科学基金资助项目(50477001)

摘　　要：比较了圆芯和椭圆芯光纤中横电场模式和能量密度分布情况,指出当椭圆芯光纤的椭圆度1<e<2.3时,传输的两个低阶模为LP01基模和eLP11模,第二高阶模为oLP11模;当e>2.3时,第二高阶模为EH11模,讨论了LP11模式的形成。结合圆芯双模光纤参数的表达式,推导出了椭圆芯光纤的模间拍长LB公式,并给出了eLP11模的归一化截止频率Vc与椭圆度e的关系,由此确定了所选椭圆芯光纤的双模工作参数。最后简要介绍了椭圆芯双模光纤在传感器中的应用。The transverse field pattern and the power distribution of modes in circular core fiber and in elliptical core fiber are compared, it is pointed out that, when the ellipticity of an elliptical core fiber is 1 〈 e 〈 2.3, the first two low order LP01 mode and even LP11 mode are transmitted, and the second higher order mode is odd LP11 mode, while e 〉 2.3, the second higher order mode is EH11 mode. The formation of LP11 mode is discussed. Combined with the expressions for circular core dual-mode fiber, the intermode beatlength of elliptical core fibers is deduced, and the relation of cut-off frequency Vc of even LP11 mode and ellipticity is given. Based on these, the dual-mode working parameters of the chosen elliptical fiber are ascertained. Finally, the application of elliptical core dual-mode fiber in sensor field is introduced briefly.

关 键 词：光纤 双模光纤 传感器 

分 类 号：TN818[电子电信—信息与通信工程]