Optical fiber sensor for localizing heating positions in multiple points using multichannel gratings with phase sampling and wavelength division multiplexing techniques

Abstract

AbstractAn optical fiber sensor system with multichannel fiber Bragg gratings (FBGs) is proposed. The gratings are designed and fabricated by phase sampling technique within strongly chirped phase masks. The sensing application can be realized at multiple points through wavelength division multiplexing (WDM) technique. It means that the different point can be monitored by different gratings, which occupies different wavelength region, according to the central pitch and chirp coefficient of phase masks. The heating position with high resolution can be analyzed through three corresponding channel shifts in the multichannel profile. In our experiment, the two multichannel gratings with channel spacing of 0.8 and 1.6 nm, respectively, are fabricated and used for sensing in two points. At last, the 400 μm accuracy of localizing the heating position is achieved. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2951–2954, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23832