Geometrical effects on the refractive index sensitivity of Mach-Zehnder fibre modal interferometers based on long-period gratings

被引：12

作者：

Caldas, P. ^{[1
,2
,3
]}

Jorge, P. A. S. ^{[1
]}

Araujo, F. M. ^{[1
]}

Ferreira, L. A. ^{[1
]}

Rego, G. ^{[1
,3
]}

Santos, J. L. ^{[1
,2
]}

机构：

[1] INESC Porto, P-4169007 Oporto, Portugal

[2] Univ Porto, Dept Fis, Fac Ciencias, P-4169007 Oporto, Portugal

[3] Escuela Super Tecnol & Gestao, Inst Politecn Viana Castelo, P-4900348 Viana Do Castelo, Portugal

来源：

MEASUREMENT SCIENCE AND TECHNOLOGY | 2009年 / 20卷 / 07期

关键词：

long-period grating; antisymmetric modes; Mach-Zehnder interferometer; pseudo-heterodyne interrogation; refractive index sensor; BIOSENSORS; SENSORS; ORIGIN;

D O I：

10.1088/0957-0233/20/7/075201

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

In this work a modal interferometer based on arc-induced long-period gratings (LPGs) in a Mach-Zehnder configuration is evaluated as a sensing structure for environmental refractive index measurement. To interrogate this sensing device, coherence addressing and pseudo-heterodyne processing were used. The influence of geometric effects such as stretching, bending and twisting the interferometer on the sensitivity to refractive index changes was studied. It is shown that due to the antisymmetric nature of cladding modes in arc-induced LPGs, it is possible to tune the system sensitivity to external refractive index by simple mechanical action. The experimental results show that it is possible to tune the sensitivity to external refractive index by more than 50% by control of the curvature in the Mach-Zehnder interferometer.

引用

页数：6

共 12 条

[1] A high sensitivity refractometer based upon a long period grating Mach-Zehnder interferometer [J].