Abstract
This paper investigates the application of single-mode silica optical fibers for capturing distributed high temperatures up to 1100°C. The optical fibers were interrogated with Luna Innovation’s optical backscattering reflectometer (OBR). The Rayleigh backscattering from the inherent inhomogeneities in the core (9 μm) was monitored to characterize the constraints of integrated SM-fiber in high-temperature environments. A relationship between time, temperature, and stress directly impacts a quality factor metric. This metric measurement is based on the degree of autocorrelation between the measured and reference Rayleigh backscattering spectra along its distributed length. Gradual creep of the natural defects in the microstructure occurs at temperatures around 750°C, and the rate of these shifts intensifies with increasing temperature, time, and stress. A continuous high-temperature measurement can be done by defining a new reference, but there is a limited time before introducing noise. This paper will demonstrate the ability of a single-mode optical fiber to temperatures up to 1100°C by defining a new reference Rayleigh spectrum. Also, the viability of an optical fiber is analyzed based on the quality factor, which provides a correlation between temperature and time.
