Chirped fiber optic Bragg grating interrogator for a Bragg grating strain sensor

Abstract

We propose a chirped Bragg grating interrogator for a uniform Bragg grating sensor. The wavelength of light reflected by the sensing grating is a function of strain. The position within the chirped Bragg gating the light is reflected from is a function of its wavelength. We determine this position by amplitude modulating the light source and measuring the phase of the reflected light and thus determine the value of the strain.