少模长周期光纤光栅模式转换器及其应用研究  

Few⁃Mode Long⁃Period Fiber Grating Mode Converter and Its Applications

作　　者：昌文喆 刘艳格[1] 冯茂 王鑫[1] 王攀[1] 王志[1] Chang Wenzhe;Liu Yange;Feng Mao;Wang Xin;Wang Pan;Wang Zhi(Institute of Modern Optics,Nankai University,Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology,Tianjin 300350,China)

机构地区：[1]南开大学现代光学研究所,天津市微尺度光学信息技术科学重点实验室,天津300350

出　　处：《中国激光》2024年第18期92-123,共32页Chinese Journal of Lasers

基　　金：国家自然科学基金(62375143)。

摘　　要：少模长周期光纤光栅(FM-LPFG),作为一种与少模光纤高度集成的模式转换器,具有转换效率高、插入损耗小、鲁棒性强、制作简单以及与光纤系统兼容等优点,在光通信系统、多横模激光器、光场调控和光传感等领域都展现出极广阔的应用前景。本文旨在综述FM-LPFG模式转换器及其应用的最新研究进展。首先,阐述了少模光纤的模式理论基础及长周期光纤光栅的模式耦合与转换机理;随后,对当前FM-LPFG的主要制造方法和特点进行了介绍,重点从高阶、宽带、多通道FM-LPFG的高效激发原理、制备方法及研究进展三方面进行了详尽的总结;最后,探讨了FM-LPFG在结构光产生、少模光纤激光器、光纤传感等领域的应用。随着现代社会对大容量信息传输和处理需求的逐年增长,新结构、高性能、多功能FM-LPFG的研制有望成为新一代光纤无源器件的重要发展方向。Significance Few-mode long-period fiber grating(FM-LPFG),as a highly-integrated mode converter with few-mode fibers,has the advantages of high conversion efficiency,low insertion loss,strong robustness,simple fabrication,and inherent compatibility with fiber systems.These characteristics make it a highly promising candidate for a wide range of applications in optical communication transmission systems,fiber lasers,and optical sensors.In this study,the research progress of few-mode long-period fiber grating mode converter and its applications are summarized.We believe that this study is valuable for all researchers interested in FM-LPFG based devices and systems.Progress It has been more than 40 years since long-period fiber gratings were proposed.In contrast to single-mode long-period fiber gratings,researchers mainly focus on the conversion between the fundamental mode and core modes for FM-LPFG,which is achieved by satisfying the phase-matching conditions between the core modes in few-mode fibers.High conversion efficiency,low insertion loss,and wide bandwidth are the key performance indicators of FM-LPFG.The precision and efficiency of FM-LPFG have been significantly improved with the continuous advancement of fabrication technology,which has further inspired researchers to explore FM-LPFG with higher orders,wider bandwidths,and more channels.Significant progress and development have been achieved in these aspects.Researchers have proposed various techniques to fabricate FM-LPFGs,thereby achieving the generation of first-to fourth-order modes with high conversion efficiencies and low insertion losses,first-to third-order modes with a 15 dB bandwidth of more than 100 nm,and first-to fourth-order modes with multiple channels.These outstanding advances not only provide new perspectives and ideas for the research of FM-LPFG but also lay a solid foundation for the promotion of the development and application of related technologies.Conclusions and Prospects This study summarizes the research progress of a few-mode

关 键 词：少模光纤 长周期光纤光栅 模式转换器 

分 类 号：TN253[电子电信—物理电子学] TN913.7