Hybrid fiber Bragg grating/long period fiber grating sensor for strain/temperature discrimination

We demonstrate a novel sensor which uses the difference in strain and temperature response of fiber Bragg gratings and a long period fiber grating to discriminate between strain and temperature induced wavelength shifts. Sensor interrogation is performed entirely on the fiber Bragg grating reflection signals, Strain and temperature were simultaneously measured to +/-9 mu strain and +/-1.5 degrees C over a wide range of conditions.