Embedded Fiber Grating Temperature Sensor System Base On Matching Method

Fiber Bragg Grating (FBG), whose refraction index has an instantly periodic modulating distribution, is a kind of new passive optical device. FBG had been proved to be one of the milestones in the history of optical communication. With the deepening of the research, its wavelength coding, anti-electromagnetism interference, corrosion resistance and good reliability, etc in sensor area advantages has been found. At the present time, Optical fiber Bragg grating sensor has been widely used in civil engineering, medicine, aerospace and other fields, and FBG sensing technology research and application are increasingly attracted people's attention.This paper starting from the actual application, the main purpose is to design one portable and meet the needs of project fiber grating temperature sensing demodulation system. Through analyzing and comparison the existing FBG sensor demodulation scheme and Combined with the actual conditions of laboratory. We proposed an embedded fiber Bragg grating temperature sensor system base on matching method.In this paper, first analyzed and research the fiber grating transmission characteristics by using the coupled mode theory. In the practical application of fiber Bragg grating sensors, existence of temperature and stress cross-sensitivity problem,according to this problem we designed a new type of sensor head package method,With this package method can resolve the problem of temperature and stress cross-sensitivity. After, according to the requirements of the system, we finished the design of the photo-detector's amplifying circuit, the A/D converting circuit based DSP2407, the timing reset circuit, the simulating port circuit and CH375 port circuit. Base on the hardware design, we complete the system software programming. Then, In order to achieve a good human-machine interactive function, we using the MFC provide by Visual C++ to write a query interface, and through the interface can finish real-time detection data observation and historical data query. Besides, it also can be achieved on the grating spectra of drawing functions.At last, we are debugging the whole system; experiments were carried out after successfully debugging the system, and did the tolerance analysis with experimental data. In the end, the experimental results show that the whole system design also complies with the expected goal.