A hybrid Raman/FBG sensing system for simultaneous measurement of temperature and strain

A hybrid Raman distributed temperature sensor (RDTS) and low-reflective fiber Bragg grating (LR-FBG) sensing system is proposed to achieve simultaneous measurement of distributed temperature and quasi-distributed strain. In this system, a method based on wavelength-swept optical time domain reflectometry (OTDR) is applied to interrogate the wavelength of reflective signal from the LR-FBGs with similar resonate wavelengths arranged in serial, while RDTS is realized by using the same light source. It is proved that such a Raman sensor and the LR-FBG sensor can be integrated into one system without interference by experiment.