[摘要]：We demonstrate the operating principle of a quasi-distributed monitoring system based on the concatenation of low-reflectance identical fiber Bragg gratings (FBGs) and interrogated by means of a photon counting optical time domain reflectometer (nu-OTDR). A filter placed in the path between the FBGs and the photon-counting OTDR impacts the height of the reflection peaks in the OTDR trace as a function of their resonance wavelength, and therefore of the measurand. The proposed technique is very easy and allows interrogating a few tens of sensors in a measurement time that does not exceed a few seconds, whatever the number of sensors.
