Ultrahigh Temperature Raman-Based Distributed Optical Fiber Sensor With Gold-Coated Fiber

An ultrahigh temperature distributed sensor based on a Raman optical-time-domain-reflectometry (ROTDR) and two types of fibers: a standard multimode fiber and multimode gold-coated fiber are experimentally validated in this paper. A calibration technique has been implemented to correct the dynamic variation of the optical loss in the gold-coated fiber. Distributed temperature measurements up to 600 degrees C have been carried out.