Quasi-distributed strain measurement for fiber Bragg grating array based on microwave photonic filter technique

Based on the microwave photonics filter technique, an FBG array for quasi-distributed strain sensing has been proposed and demonstrated. The kernel of this work is that the strain on the FBG array changes the wavelength of these FBGs, which is converted to the variation of the time delay of the time response of the generated microwave photonic filter. Results show that, there is good measurement linearity between the time delay and applied strain. The proposed scheme enjoys fast interrogation speed and high resolution, hoping to provide a valuable reference in the field of temperature, index refractive and other parameters sensing.