Study on Demodulation Algorithm of Fiber Optic Fabry-Perot Sensors Based on Spectrum Adjusting

摘要

This paper aims at proposing a modified algorithm based on spectrum adjusting. The theoretical analysis of the error between the real light source spectrum and the Gaussian spectrum is presented. The hardware of the demodulation system is introduced, including the coupler, collimation lens, volume phase grating, focus lens, CCD array, A/D card, and PC. The modified algorithm will adjust the interferometric spectrum of the sensor by getting rid of the effect of the light source spectrum. Experiment was carried out to test the performance of the demodulation system. It can be found from the result that the algorithm has improved the accuracy of the demodulation system significantly. The demodulation accuracy for the strain sensor is better than 0.5 microstrain.