Study On Transform Demodulation Theory Of Optical Fiber Fabry-Perot Sensor And Implementation Of Embedded System

Optical fiber Fabry-Perot sensor is one of the earliest optical fiber sensor used in practical engineering mainly due to their, (a) miniature, (b) high sensitivity, (c) stable performance, (d) immunity from electro-magnetic interference, (e) remote signal processing ability, and, (f) multiplexing capabilities. With the occurence of new technique, reseach of optical fiber grating sensor became hot topic gradually while reseach of optical fiber Fabry-Perot sensor remained previous stage. Compare with optical fiber grating sensor, although optical fiber Fabry-Perot sensor has shortcoming in sensor multiplexing , it has the merit of high stabilization, suiting for long term monitoring of parameter. Therefore, optical fiber Fabry-Perot sensor has important practical value in many domain. However, as the reason of commercial benefit, the emphasis of current the sensor technique is the study of polytechnic technique. Comparatively, theoretical study is ignored, restricting the promotion of polytechnic technique. Hence, enriching and perfecting theory of optical fiber Fabry-Perot sensor is of important significance in enhancing its application technique. Starting with demodulation theory of optical fiber Fabry-Perot sensor, theory system of Fourier transform demodulation was studied and correlating demodulation theory was presented in this paper. Besides, embedded demodulation system of optical fiber Fabry-Perot sensor was designed and manufactured by using advanced embedded technique. Detailed contents are given as follows:(1) Beginning with basis principal of Fourier transform demodulation, strict theory model of optical fiber Fabry-Perot sensor was established, the influence of important parameter to accuracy of Fourier transform demodulation was analyzed, and therefore rationality of approximate model in ideal light source and dual beam interference was interpreted, then demodulation algorithm of Fourier transform was deeply studied, including that practical interpolating algorithm was presented, and the feasibility of direct performing FFT to the data, which sampled at equal optical wavelength interval, was analyzed, and the accuracy of descret gap transform was proved in theory. The next, Correlating demodulation scheme was presented by synthesizing and summarizing cavity length matching demodulation, and realized method was discussed. At last, the combinatorial output characteristics of serial and parallel multiplexed sensors were discussed in details, the feasibility of demodulating multiplexed signal with Fourier...