用于光纤F-P声压传感器的直流补偿解调技术研究

Research on DC Compensation Demodulation Technology for Optical Fiber F-P Sound Pressure Sensor

提出了一种改进的双腔直流补偿技术,用于解调非本征法布里-珀罗干涉(EFPI)光纤传感器,以消除腔长差与入射光波长相匹配的要求。通过消除直流分量和校准信号相位,可以从具有任意相位差的原始信号中获得两路正交信号。通过理论仿真,制作了具有不同腔长差的EFPI光纤传感器,对所提出的方法进行了试验验证。结果表明,该方法在解调双FP腔EFPI传感器时,不需要保证初始相位差恒定,且对腔长漂移不敏感,具有良好的稳定性和实用价值。

A modified dual-cavity DC compensation technique is proposed to demodulate the Extrinsic Fabry-Perot interference(EFPI)fiber sensors,in order to eliminate the requirement of matching between the cavities’difference and the light’s wavelength.Two quadrature phase-shifted signals could be obtained from the original signals with arbitrary phase difference by eliminating the direct-current component and calibrating the signals’phases.Detailed theoretical simulation is carried out.EFPI sensors with different cavity length differences are fabricated,and the proposed method is verified by experiments.The results show that this method does not need to keep the initial phase difference constant when demodulating the dual F-P cavity EFPI sensor,is insensitive to the cavity length drift,and has good stability and practical value.