干涉型光纤传感器相位生成载波技术研究与改进

Analysis and Improvement of the Phase Generator Carrier Method in Fiber Interferometer Sensors

对干涉型光纤传感器的相位生成载波解调技术进行了研究.对PGC算法进行了数学推导和仿真计算,对数字低通滤波器进行了详细分析,给出了其影响PGC解调性能的原因及数字滤波器的设计方法.讨论了传感器干涉光强对PGC算法输出结果的影响,提出了改进的PGC算法,该算法可以有效的实现自动增益控制,消除干涉光强漂移对解调的影响,并大大减小由干涉光强引入的系统噪音;还可以在有限阶数低通滤波器的情况下,极大的增加系统可解调的大信号幅度,提高系统动态范围12dB以上.

Th investigated. key technolo performance sensor light e Phase Generator The digitized PGC d gy digital low pass of the PGC demodula power to the output Carrier emodula filter is tion and of the （PGC） method in fiber interferometer was proposed and tion was mathematically deduced, calculated and emulated. The analyzed detailedly, the reason why the filter influence the the design method of the filter is presented. The influence of the PGC demodulation is discussed. The modification of the PGC demodulation algorithm is introduced. This improvement has several advantages compared with the prototype of PGC algorithm. Auto Gain Control （AGC） is achieved effectively,the shift of the light power is eliminated and will not be transferred to the output, and at the same time the noise from the light power is reduced much. The influence of the low-pass filter is relieved, so it has a much higher upper limit with the less exponent number filter. It could improve the performance of the system with the same resource consumption,increase the dynamic range more than 12 dB.