基于空间干涉成像的七芯光纤芯间群延时差测量  

Inter-core Differential Group Delay Measurement of Seven Core FiberBased on Spatial Interference Imaging

作　　者：沈立翠 黄素娟 陈伟 闫成 赵欣鹏 SHEN Licui;HUANG Sujuan;CHEN Wei;YAN Cheng;ZHAO Xinpeng(Key Laboratory of Specialty Fiber Optics Access Networks,School of Communication and Information Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学通信与信息工程学院,特种光纤与光接入网重点实验室,上海200444

出　　处：《光子学报》2023年第7期159-167,共9页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.62075125,62275148);上海市科委项目(Nos.19DZ2294000,20DZ2204900);江苏省产业前瞻与关键核心技术-重点项目(No.BE20222055-4)。

摘　　要：提出了基于空间干涉成像的多芯光纤芯间群延时差的测量方法。用CCD记录不同波长下的空间干涉图,利用干涉图中所有像素点的干涉信息构建三维空间干涉光谱,并通过光谱分析可得芯间群延时差。搭建了基于空间干涉成像的多芯光纤芯间群延时差测量实验装置,测量了沟槽辅助型弱耦合七芯光纤芯间群延时差。该方法的测量装置简单,测量精度可达10~(-4)ps/m,不仅可测量两芯间的延时差还可同时测量任意相邻的多个芯的芯间延时差。测量时使用三维调节台加CCD的组合使得待测纤芯的选择激发更加简单。此外,还研究了多芯光纤芯间延时差的弯曲依赖性,结果显示,随着弯曲半径的增大,多芯光纤芯间群延时差不断减小。Using different cores of a Multi-Core Fiber(MCF)as independent parallel spatial paths to transmit different information simultaneously offers cost,space and energy savings.The inter-core Differential Group Delay(DGD)is a key parameter of the multi-core fibers,and its accurate measurement is of great importance.In the multi-core fibers,errors in the preparation process or bending of the fiber caused by external forces can result in inter-core differential group delay in various cores.When light is transmitted in a multi-core fiber,the outgoing light from different cores will interfere with coherent superposition in space due to different group delays.According to this character,this paper proposes a spatial interferometric imaging-based method for measuring the inter-core differential group delay of multi-core fibers,and building an experimental measurement device.At the input of the multi-core fiber,the laser is shifted and injected by adjusting the three-dimensional adjustment table to excite different cores,and the output light of the excited cores will interfere in space.The computer controls the CCD to scan the wavelength of the input light in one dimension and records the spatial interferogram at different wavelengths in real time.The interferometric information of all pixels in the interferogram is used to construct a three-dimensional spatial interferometric spectrum,and the inter-core differential group delay of the multi-core fiber can be obtained by spectral analysis of the interferometric spectrum.The inter-core differential group delay of the weakly linked trench assisted seven core fiber is measured in this paper.We measured the inter-core differential group delay between the central and six outer cores respectively.When two cores are excited at the same time,a peak will appear at the delay difference between the two cores through the Fourier transform of the interference information.Subtracting the-inter core differential group delay between the central core and two adjacent outer cores yields the i

关 键 词：空间干涉成像 光谱分析 弱耦合七芯光纤 芯间群延时差 弯曲依赖性 

分 类 号：TN253[电子电信—物理电子学]