基于Sagnac干涉仪的光纤耦合器耦合相移检测技术  

Coupling Phase Shift Detection Technology of Fiber Coupler Based on Sagnac Interferometer

作　　者：王瑞琴 杨远洪[1] 李慧[1] Wang Ruiqin;Yang Yuanhong;Li Hui(School of Instrumentation.Science and Opto-Electronics Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《中国激光》2022年第9期88-95,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(61227902,U1637106);国家重点研发计划(2018YFC1503703);创新团队发展计划(IRT1203)。

摘　　要：提出了一种基于混合Sagnac干涉仪的光纤耦合器耦合相移检测技术,其中混合Sagnac干涉仪由待测单模光纤耦合器和保偏光纤组成。基于混合Sagnac干涉仪互易端口和非互易端口输出干涉光谱的谷值波长特征,推导出单模光纤耦合器耦合相移检测方程并进行了测试误差分析。搭建了实验系统,实现了固定分光比3×3单模耦合器以及不同分光比2×2单模耦合器耦合相移的高精度检测,并首次实现了不同温度条件下2×2单模耦合器的耦合相移变化特性测量,实验结果与理论估计一致。理论分析和实验研究结果表明,所提检测方法实施方便、检测精度高,适应性强,为光纤耦合器耦合相移的定量精确测试和分析提供了有效手段。Objective The optical fiber coupler is the basic device in an optical fiber sensor system.The phase relationship between the outports of the coupler,that is,the coupling phase shift,has a significant impact on the performance of the sensor system.An accurate measurement of the coupling phase shift and its variation characteristics are of great value to the development of high-performance fiber couplers and the improvement in the performance of their application systems.As the mainstream method for the theoretical analysis of coupling phase shifts,the scattering matrix analysis method has many ideal assumptions in the analysis process,resulting in a large gap between the calculated results and real phase shifts.Besides,the coupling phase shift is susceptible to external factors such as temperature.Therefore,the theoretical analysis has great limitations,and the exact coupling phase shift value must be determined through the experimental test.At present,the existing experimental detection scheme is based on the Mach-Zehnder interferometer,and the coupling phase shift is calculated by detecting the output power of each port using the phase modulation technology.The detection accuracy is influenced by photoelectric conversion,optical path loss,coupler performance,modulation signal,and other factors,and thus there is a large error.The highest detection accuracy that can be achieved in the existing reports is 0.229°.In this study,we propose a novel coupling phase shift detection technology based on the hybrid Sagnac interferometer,which uses wavelength demodulation to achieve the coupling phase shift detection,so as to improve the detection accuracy and the ariti-interference of the detection device.It is hoped that the proposed detection technology can provide an effective means for the quantitative and accurate test and analysis of the coupling phase shift of the single-mode fiber coupler.Methods The coupling phase shift detection technology proposed in this paper is based on a hybrid Sagnac interferometer structure

关 键 词：光纤光学 单模光纤耦合器 耦合相移 SAGNAC干涉仪 

分 类 号：TN253[电子电信—物理电子学]