High performance Raman distributed high-temperature sensing system based on sapphire fiber

Distributed high-temperature sensing (DHTS) system with single crystal fiber (SCF) has been proved to be an efficient method for ultra-high temperature sensing where traditional silica fiber can't survive. The performance enhancement of the system has been a long desire to better support various applications. In this paper, the upgraded DHTS system used 532 nm laser to avoid thermo-noise at ultra-high temperature and detected the backscattered Raman Stokes and Anti-Stokes signals in a sapphire fiber. The measurands indicated a 7 cm spatial resolution and a 2.2. temperature resolution with only 30 s average time. The system is expected to be applicable for important applications such as aircraft engine and energy monitoring with further improvements.