Research On Fiber Bragg Grating Sensing Network Testing System Of F-P Demodulation Based On ARM

Fiber Bragg Grating (FBG) Sensor is one of the heat topics in the optical fiber grating sensing technique fields in the last few years. It can work correctly in such formidable conditions as strong electromagnetic field, high temperature, corruptive and explosive conditions, what's more, it is easy to form FBG arrays by connecting single ones in series, based on which contribution sensing is realized. This is the only merit that belongs to FBG.FBG sening network testing system of tunable Fabry-Perot demodulation is proposed in this paper, optical part and electric circuit part are concluded in the system. In optical part, basic knowledge of FBG demodulation technology is introduced firstly, then some demodulation methods about normal wave-length are analysed and compared. The fiber grating Fabry-Perot demodulation is employed because Fabry-Perot has broad tunable range and can measure multi-point parameter. This method is researched and analysed theoretically. The cavity length and the reflectivity of Fabry-Perot is optimized by using Matlab simulation. In the second part, the trimming circuit is designed to convert the output signal of photodetector into rectangle pulse signal and the hardware circuit of signal processing is designed to prove the feasibility of the algorithm. The LPC2214 processor of Philips, is used as the core processor for the circuit. Power circuit, Reset circuit, Serial ports, JTAG ports and Led displaying circuit are concluded in the circuit part. About software, related programs and fake signal are designed. Finally, the fake signal is adopted as the signal of the testing system, to testify the experimental validation and obtained the experimental data. And the feasibility of the testing system is proved through analysis.