摘要
阐述了干涉型光纤水听器外差检测的基本原理,对干涉型光纤水听器数字化外差检测方法动态范围上限进行了研究。理论分析了由外差频率决定的动态范围上限以及反正切、微分-交叉相乘(DCM)两种正交解调算法决定的动态范围上限,并进行了综合对比。分析结果表明,不同的外差频率所能达到的动态范围上限不同;相同的外差频率结合不同的正交解调算法,所能达到的动态范围上限也不相同。在固定采样率下,设置外差频率为采样率的1/4,并结合反正切算法,可以实现更大的动态范围上限。数值模拟证明了理论分析的正确性。构建了基于外差检测的光纤水听器系统并进行了实验研究,实验结果与理论相符,证实了采用外差检测方法实现大规模光纤水听器阵列更大动态范围检测的可行性。
The principle of fiber optic interferometric hydrophone using heterodyne detection scheme is introduced and the upper limit of dynamic range of the digital heterodyne detection is analyzed in detail. The upper limits of dynamic range decided by heterodyne frequency and the arctangent or differential cross-multiply （DCM） quadrant demodulation algorithm are analyzed in theory and compared with each other. Analysis results indicate that the upper limit of dynamic range changes with heterodyne frequency. However, with the same heterodyne frequency, different upper limits of dynamic range are achieved with arctangent or DCM algorithm. The upper limit of dynamic range can achieve a higher value when the heterodyne frequency is equal to a quarter of the sampling rate and the arctangent quadrant demodulation algorithm is adopted. Numerical simulation validates the theoretical analysis. A fiber optic hydrophone system based on heterodyne detection technique is constructed and the experimental results, which correspond to the theoretical results, demonstrate the feasibility of the fiber optic hydrophone to achieve large dynamic range and large-scale array.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2011年第8期84-90,共7页
Acta Optica Sinica
基金
高等学校博士学科点专项科研基金(20104307110020)资助课题
关键词
光纤光学
光纤水听器
信号检测
外差
动态范围上限
fiber optics
fiber optic hydrophone
signal detection
heterodyne
upper limit of dynamic range
