一种消除伴生调幅的光源调频型相位生成载波解调方法  

Frequency-modulated phase generated carrier demodulation for eliminating companion amplitude modulation

作　　者：施清平[1,2] 王利威[2] 张敏[2] 田芊[1] 廖延彪[2] 

机构地区：[1]清华大学精密仪器与机械学系精密测试技术及仪器国家重点实验室,北京100084 [2]清华大学电子工程系光纤传感研究中心,北京100084

出　　处：《光电子．激光》2011年第2期180-184,共5页Journal of Optoelectronics·Laser

基　　金：国家"863"计划资助项目(2006AA0AA102-03)

摘　　要：为了克服伴生调幅对光源调频型相位生成载波(PGC)解调方法的影响,提出一种基于双路干涉信号和微分-交叉相乘(DCM,differential-cross multiply)的PGC解调方法。通过3×2耦合器引入双路干涉信号,直接调制光源频率获得相位载波。实验结果表明,新方法较好地消除了光源伴生调幅的影响。对于4 rad的解调信号,总谐波比提高20 dB以上,幅值偏差为0.08 rad,而单路干涉信号的DCM-PGC方法的偏差达0.33 rad。并且,新方法的信噪比和信纳比均有显著的改善。In order to eliminate the effect of amplitude modulation in the source with direct frequency modulation（DFM） on phase generated carrier（PGC） demodulation approach,a new PGC method was proposed based on differential-cross multiply（DCM） and double interferometric signals by a 3×2 directional coupler.Experimental results confirm that the new scheme has eliminated the effect of the companion amplitude modulation on demodulation very well.For a demodulation signal of 4 rad,the total signal-harmonic-ratio（SHR） increases by more than 20 dB,and the amplitude deviation of this new method is 0.08 rad,while it is up to 0.33 rad by the DCM-PGC approach for a single interferometric signal.Besides,the signal-tonoise ratio（SNR） and signal-to-noise-and-distortion（SINAD） are also improved significantly.

关 键 词：干涉型光纤传感器 直接调制 伴生调幅 相位生成载波(PGC) 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]