Differential Fiber Optic Sensor Based on Bragg Gratings

The paper considers the problem of differential measurement of temperature or strain. A measurement method using two Bragg fiber gratings is proposed, which allows microdeformations and minimal temperature deviations to be measured with high sensitivity, while the measuring circuit remains quite simple in design and inexpensive. The type of fiber Bragg grating necessary for providing a wide range of measurements and stability of characteristics is selected. The transfer characteristic of the sensor is considered, the optimal range of the sensor is determined to ensure a linear characteristic. Variants of using the sensor both as a converter and as a discrete sensitive element are proposed.