Ultra-low-loss all-fiber orbital angular momentum mode-division multiplexer based on cascaded fused-biconical mode selective couplers  

作　　者：Huiyi Guo Yan-ge Liu *Liang Chen Wenzhe Chang Zekun Shi Letian Gu and Zhi Wang 

机构地区：[1]Nankai University,Institute of Modern Optics,Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology,Tianjin,China

出　　处：《Advanced Photonics Nexus》2024年第1期43-52,共10页先进光子学通讯（英文）

基　　金：supported by the National Key Research and Development Program of China (Grant No.2018YFB1801802);the National Natural Science Foundation of China (Grant Nos.62375143 and 61835006).

摘　　要：Mode-division multiplexers(MDMUXs)play a pivotal role in enabling the manipulation of an arbitrary optical state within few-mode fibers,offering extensive utility in the fields of mode-division multiplexing and structured optical field engineering.The exploration of MDMUXs employing cascaded resonant couplers has garnered significant attention owing to their scalability,exceptional integration capabilities,and the anticipated low insertion loss.In this work,we present the successful realization of high-quality orbital angular momentum MDMUX corresponding to topological charges 0,±1,and±2,achieved through the utilization of cascaded fused-biconical tapered couplers.Notably,the measured insertion losses at 1550 nm exhibit remarkable minimal values:0.31,0.10,and 0.64 dB,respectively.Furthermore,the 80%efficiency bandwidths exceed 106,174,and 174 nm for these respective modes.The MDMUX is composed of precisionmanufactured high-quality mode selective couplers(MSCs).Utilizing a proposed supermode propagation method based on mode composition analysis,we precisely describe the operational characteristics of MSCs.Building upon this comprehensive understanding,we embark on a pioneering analysis elucidating the influence of MSC cascading order on the performance of MDMUXs.Our theoretical investigation substantiates that when constructing MDMUXs,MSCs should adhere to a specific cascading sequence.

关 键 词：space-division multiplexing all-fiber devices orbital angular momentum 

分 类 号：TN2[电子电信—物理电子学]