空间扫描型光纤法布里珀罗传感解调中LED光源的影响研究

Research on LED Effect in Spatial Scanning Optical Fiber Fabry-Perot Sensing Demodulation System

结合恢复单色频率绝对相位解调算法研究了光源输出参数对空间扫描型光纤法布里珀罗传感解调影响。建立了相位解调值随光源中心波长变化的数学模型,通过改变光源光功率和光谱进行了解调实验研究。结果表明压力解调值的误差值与光源输出光功率有关;当温度升高时光源光谱会产生红移,使压力解调值产生误差;解调值与光源光谱中心波长满足二次函数关系。实验结果与理论分析一致,在140kPa范围内保证0.1%的解调误差时,光源光谱中心波长波动小于1.79nm。

The impact of optical source on the accuracy in recovery monochromatic frequency absolute phase demodulation algorithm for optical fiber Fabry-Perot sensor is studied in this paper. The relationship between phase demodulation value changes and the output spectrum of optical source is discussed both in theoretical aspect and demodulation experiment. Results show that the demodulating error has a relationship with the light source optical power. When the temperature changes from low to high, the source spectrum＇s redshift causes pressure demodulation value error. The demodulation results show a quadratic relationship with various central wavelength of optical source, which is consisted with the theoretical analysis. Within the pressure range of 140 kPa, the central wavelength fluctuation of fight source should be lower than 1.79nm when O. 1% demodulation error is needed.