The Impact of Optical Fiber Type on the Temperature Measurements in Distributed Optical Fiber Sensor Systems

This paper presents the capabilities of using distributed optical fiber sensors to obtain the temperature profile of an optical path made of silica telecom optical fiber. The impact of the optical fiber type on the temperature measurements is also observed. Two types of optical fibers are tested: standard G.652.D and low-loss G.654.C. DOFS systems for temperature measurements are based on the phenomenon of Raman or Brillouin backscattering. In case of Brillouin-based systems, the spectral properties depend on the type of optical fiber and its parameters. The Brillouin frequency shift depends on the temperature around the fiber, as well as the strain applied to the optical fiber. The presented results show that temperature coefficient can also vary depending on the optical fiber type. For the standard G.652.D optical fiber, the temperature coefficient equals 1.12 MHz/°C and 1.14 MHz/°C depending on the tracked peaks, while for the low-loss G.654.C fiber it equal 1.4 MHz/°C.