抑制光纤检波器系统光强波动影响的解调方法  

Demodulation method to suppress the influence of laser intensity disturbance in optical fiber hydrophone system

作　　者：王凯[1] 田长栋[2] 施清平[2,3] 王利威[2] 段发阶[1] 张敏[2] 廖延彪[2] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]清华大学集成光电子学国家重点实验室,北京100084 [3]北京宇航系统工程研究所,北京100076

出　　处：《红外与激光工程》2013年第6期1593-1600,共8页Infrared and Laser Engineering

基　　金：国家"863"计划(2006AA0AA102-03)

摘　　要：基于海上油藏勘探领域的光纤检波器光电复合空分阵列系统,通过两路PGC干涉检波信号相除以构造非线性函数,提出了一种采用查找表实现该非线性函数解调的新方法。相比传统的两路PGC干涉检波信号线性组合的反正切解调方法,构造非线性函数解调新方案不仅可以补偿生成载波时直接调制DFB光源带来的高频光强波动干扰,也可以抑制其他因素造成的光强随机波动给采用定常系统参数解调带来的影响。实验结果表明:内调制DFB激光器,采用非线性函数解调方案比线性组合方案在谐波抑制方面优势明显,两者HSR平均值相差达26.37 dB;当系统光强降低50%,非线性函数解调方案的结果 HSR平均值优于线性组合方案得到的结果,两者相差达17.53 dB。A novel demodulation method called nonlinear function scheme and realized by Lookup Table （LUT） technique was proposed in the optical fiber hydrophone array based on the spatial division multiplexing optoelectronic system for the application of oceanic oil exploration. The nonlinear function was obtained by dividing two channels of PGC interference detection signal. Compared with the traditional manner using arctangent algorithm to the linear combination of the two channels of detection signal, the nonlinear function scheme not only can compensate an effect of accompanying laser intensity modulation caused by direct alternating current injection to the DFB laser, but has the characteristic of suppressing an influence of random laser intensity disturbance on the PGC system using constant parameters to demodulate as well. Experimental results demonstrate that in the condition of directly modulating DFB laser, the nonlinear function demodulation scheme has an overwhelming superiority over the linear combination method in harmonic suppression performance and the difference of HSR meanvalue between the two demodulation schemes reaches 26.37 dB. When intensity in the system decreases by 50%, HSR mean value of the nonlinear function demodulation is larger than that of the linear combination and the difference reaches 17.53 dB.

关 键 词：光纤检波器 相位生成载波 光强波动 伴生调幅 非线性函数 查找表 

分 类 号：TN2[电子电信—物理电子学] TN76