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

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Caldas, P (Author) Other; Jorge, PAS (Author) FCUP; Araujo, FM (Author) Other; Ferreira, LA (Author) Other; Rego, G (Author) Other; Santos, JL (Author) FCUP

Journal

Title: Measurement Science and Technology

Vol. 20

Final page: 075201

ISSN: 0957-0233

Publisher: Institute of Physics Publishing

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 10 Citations

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

Other information

Authenticus ID: P-003-HZ5

DOI: 10.1088/0957-0233/20/7/075201

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific