Self-referenced wavelength-sensitive monitoring technique for quasi-distributed fiber Bragg grating sensors
C. Caucheteur, D. Kinet, N. B. Soltana, P. Mégret, M. Wuilpart, University of Mons (Belgium)
In this work, we demonstrate the operating principle of a quasi-distributed monitoring system based on the concatenation of identical low reflective fiber Bragg gratings (FBGs) interrogated by means of an optical time domain reflectometer (OTDR). A filter inserted between the OTDR and the FBGs allows the height of the FBG reflection peaks in the OTDR trace to depend on their resonance wavelength, and therefore to the measurand. The proposed configuration is kept very basic and cost-effective, as a standard OTDR and some passive components are used. It is suited to interrogate a few tens of sensors in a measurement time that does not exceed a few seconds, whatever the number of sensors.
