Investigation of Raman fiber laser temperature probe based on fiber Bragg gratings for long-distance remote sensing applications

We demonstrate a practical and simple, all fiber Bragg grating (FBG) based Raman laser sensing probe for long-distance, remote temperature sensing application. Using multiple laser cavities based on FBG's and a tunable chirped FBG, we obtain the simultaneous multichannel remote temperature sensing operation at a 50 km distance. The temperature sensitivity is measured to be 7.15 pm/°C.