为探究光纤法布里-珀罗传感器条纹计数法的解调准确度, 对基于波峰波谷复合算法的条纹计数法的腔长解调误差及其影响因素进行了理论推导、仿真分析和实验验证.结果表明: 光纤法布里-珀罗传感器干涉光谱的干涉级次及干涉级次差、波峰波谷的位置准确度是影响解调准确度的主要因素; 干涉级次随腔长的变化导致腔长解调结果产生周期性跳动误差, 跳动周期约为光源中心波长的1/4; 周期性跳动误差的幅度受波峰波谷位置准确度的影响, 波峰波谷位置准确度越低, 周期性跳动误差幅度越大, 腔长解调误差越大.

To investigate the demodulation accuracy of fringe counting method for optical fiber Fabry-Perot sensor, the cavity length demodulation error of the fringe counting method based on the composite algorism of crest and trough, and its influence factors that may cause demodulation errors were studied theoretically and experimentally. Results show that, the main influencing factors are interference ordersand location errors of spectral peaks and valleys. The variations of interference orders with the cavity length will cause periodic jitter demodulation errors, and the period equals a quarter of the center wavelength of light souce. Location errors of spectral peaks and valleys determine the magnitudeof demodulation errors, that is, the larger the location errors are, the larger the demodulation errors will be.