Randomly coupled trench-assisted multicore fibers with different arrangements for high tolerance of manufacturing errors

作     者：Yongneng JIANG Jiajing TU Shecheng GAO Weiping LIU Zhaohui LI 

作者机构：Department of Electronic Engineering College of Information Science and Technology Jinan University School of Electronics and Information Technology Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) 

出 版 物：《Science China(Information Sciences)》 (中国科学:信息科学(英文版))

年 卷 期：2023年第66卷第11期

页      面：260-272页

核心收录：

学科分类：0810[工学-信息与通信工程] 0808[工学-电气工程] 08[工学] 0803[工学-光学工程] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported by National Key Research and Development Program of China (Grant No. 2021YFB2800901) National Natural Science Foundation of China (Grant Nos. U2001601, 62035018) Guangzhou Basic and Applied Basic Research Foundation (Grant No. 202002030327) Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515012984) 

主　　题：manufacturing errors randomly coupled multicore fibers trench-assisted core single-layer arrangement double-layer arrangement 

摘      要：Randomly coupled multicore fibers(RC-MCFs) are promising candidates for long-haul transmission. However, the degree of coupling between the homogeneous cores of an RC-MCF is weakened if manufacturing errors appear. Therefore, a low-index trench layer is introduced into the coupled cores to investigate the effects of its position and thickness on the group index to enhance the tolerance of manufacturing errors. A depressed region is designed in the center of the core to solve the problem of the effective area decreasing because of the confinement of the low-index trench. Additionally, it is important to study the effective arrangement of the coupled cores to obtain a smaller group delay spread(GDS) within the limited 125-μm cladding; we discuss the single-layer and double-layer arrangements. A moderate range is found for both the bending radius and core pitch to minimize the GDS. For the single-layer arrangement, the degree of mixing is weak, and the degeneracy state does not easily change the bending conditions; thus, it may be a good candidate for designing systemically coupled multicore fibers. For the double-layer arrangement, the bending and twisting factors can induce sufficient mixing among the different modes to reduce GDS; thus,this arrangement is more suitable for the design of RC-MCFs.