Chirped Fiber-Optic Bragg Grating Interrogator in a Multiplexed Bragg Grating Sensor Configuration

This paper presents a chirped grating interrogator for fiber Bragg grating sensors. The interrogator uses the wavelength dependence of the phase group-delay response of a chirped fiber Bragg grating to determine the Bragg wavelength of the sensor. The sensitivity of the interrogator is determined by the selection of the grating length and the bandwidth. The experimental results demonstrated strain measurements over a range of more than 10 000 /spl mu/m per meter. Multiplexing can be achieved by using an arrayed-waveguide grating that allows the interrogation of more than one grating sensor with a single chirped grating.