Open AccessAll-fiber Mach-Zehnder interferometers for sensing applications
Author(s) -
Lecheng Li,
Li Xia,
Zhenhai Xie,
Deming Liu
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.011109
Subject(s) - materials science , optics , interferometry , fusion splicing , multi mode optical fiber , fiber optic sensor , mach–zehnder interferometer , cladding (metalworking) , refractive index , graded index fiber , astronomical interferometer , single mode optical fiber , dispersion shifted fiber , cladding mode , sensitivity (control systems) , optical fiber , polarization maintaining optical fiber , photonic crystal fiber , wavelength , optoelectronics , physics , electronic engineering , metallurgy , engineering
We propose and demonstrate a thinned fiber based Mach-Zehnder interferometer for multi-purpose sensing applications. The sensor head is formed by all-fiber in-line singlemode-multimode-thinned-singlemode (SMTS) fiber structure, only using the splicing method. The principle of operation relies on the effect that the thinned fiber cladding modes interference with the core mode by employing a multimode fiber as a mode coupler. Experimental results showed that the liquid refractive index information can be simultaneously provided from measuring the sensitivity of the liquid level. A 9.00 mm long thinned fiber sensor at a wavelength of 1538.7228 nm exhibits a water level sensitivity of -175.8 pm/mm, and refractive index sensitivity as high as -1868.42 (pm/mm)/RIU, respectively. The measuring method is novel, for the first time to our knowledge. In addition, it also demonstrates that by monitoring the wavelength shift, the sensor at a wavelength of 1566.4785 nm exhibits a refractive index sensitivity of -25.2935 nm/RIU, temperature sensitivity of 0.0615 nm/°C, and axial strain sensitivity of -2.99 pm/με, respectively. Moreover, the sensor fabrication process is very simple and cost effective.