A Novel Idea to Discriminate Strain and Temperature Variations of Fiber Bragg Grating Sensor

Recently, there is a growing requirement for smart structures that has led to an increase in research on the fiber optic sensors as a sensing element. Unlike other fiber optic sensors, a fiber Bragg grating (FBG) sensors can measure the strain and temperature with an ease when compared to other sensors, with relatively less changes in the reflected wavelength. In Addition to this, FBG sensors can be easily embedded into a variety of structures because of their small size and wide temperature range. Since Bragg wavelength changes with both strain and temperature, it is difficult to identify whether the change of wavelength is due to variation in strain or temperature. There are several ways to discriminate between these parameters. Since most of the methods are not easy to implement. Most of the methods include complex design structures with more than one FBGs. This research proposes a simple method to discriminate between strain and temperature variation by measuring the full width half maxima of the reflected spectra of Bragg grating by using a single FBG sensor.