High-temperature fiber Bragg grating sensors in microstructured fibers for harsh environment applications

Abstract

In this paper, we present fiber Bragg grating pressure sensors written in twin-hole microstructured fibers for high temperature operation above 800 °C. A Ti: Sapphire ultrafast laser is used to inscribe type II grating in two-hole optical fibers. The fiber Bragg grating resonance wavelength shift and peak splits are studied as a function of external hydrostatic pressure from 15 psi to 2000 psi. The ultrafast laser inscribed grating pressure sensor shows stable and reproducible operation above 800 °C. This paper demonstrates highly multiplexible pressure sensor technology for high temperature environment.