Bragg grating-based interferometric fiber optic sensors

The paper describes a new fiber-optic sensing technique using Bragg grating-based interferometers. This technique joins advantages. of the fiber Bragg grating and interferometric sensor. Sensing interferometers have been formed by pairs of identical closely spaced low reflective Bragg gratings imprinted in the core of single mode fiber. A digital signal processing of interference fringes in the sensor reflection spectrum has been developed. It extends multiplexing capabilities of the fiber Bragg grating-based sensor and provides absolute and high-resolution measurements in a wide dynamic range. Experimental results on testing the sensor performance for strain and temperature measurements are presented.