Fabrication and characterization of multimode optical fiber sensor for chemical temperature monitoring using optical time domain reflectometer

In this work, the optical fiber sensor system to measure the optical loss due to temperature variation of gasoline and toluene was papered. The optical fiber sensor was characterized using optical time domain reflectometer (OTDR). The sensor was a 50 cm multimode fiber with about 1-3 cm at its central region being partially unclad. The partial uncladding was carried out using chemical etching technique. The optical loss of sensor was measured when unclad part exposed to gasoline and toluene respectively at different temperature ranging from 25 °C to 60 °C. The optical loss of sensor increases in a step drop of OTDR trace as the temperature is increased. The rate of optical loss was estimated to be 0.01576 dB/°C and 0.02212 dB/°C for gasoline and toluene respectively.