Edge Based Fiber Bragg Grating Interrogator

Abstract

Fiber Bragg Grating (FBG) interrogation system based on spectral edge characteristics of Chirped Fiber Bragg Grating (CFBG) is reported to measure temperature of hot water bath. We use in-house fabricated FBG and CFBG as an edge filter in developing FBG interrogator. The CFBG transmission profile at rising and falling edge varies linearly with wavelength. The Bragg wavelength of FBG as a function of temperature forms the basis of temperature measurement. The ratio of optical intensity of Bragg wavelength due to edge slope of CFBG and intensity of the Bragg wavelength vs. temperature of water bath observed is linear. Using the slope of linear curve, the temperature measurement resolution of 0.30C with temperature range of 300C was achieved