低损耗大带宽双芯负曲率太赫兹光纤偏振分束器  

Dual-core negative curvature fiber-based terahertz polarization beam splitter with ultra-low loss and wide bandwidth

作　　者：惠战强 高黎明 刘瑞华 韩冬冬 汪伟[2] Hui Zhan-Qiang;Gao Li-Ming;Liu Rui-Hua;Han Dong-Dong;Wang Wei(School of Electronic Engineering,Xi’an University of Posts and Telecommunications,Xi’an 710121,China;State Key Laboratory of Transient Optics and Photonics,Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710119,China)

机构地区：[1]西安邮电大学电子工程学院,西安710121 [2]中国科学院西安光学精密机械研究所,瞬态光学与光子技术国家重点实验室,西安710119

出　　处：《物理学报》2022年第4期324-335,共12页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61875165,61775180,61772417);陕西省教育厅协同创新项目(批准号:20JY060);西安邮电大学研究生创新工作站(批准号:YJGJ201905)资助的课题。

摘　　要：设计了一种基于双芯负曲率光纤的新型低损耗大带宽太赫兹偏振分束器,该器件以环烯烃共聚物为基底,沿圆周等间距分布着12个含内嵌管的圆形管,通过上下对称的两组外切小包层管将纤芯分成双芯.采用时域有限差分法对其导模特性进行分析,详细研究了各个参数对其偏振分束特性的影响,分析了该偏振分束器的消光比、带宽、传输损耗等性能.仿真结果表明:当入射光频率为1 THz,分束器长度为6.224 cm时,x偏振光的消光比达到120.8 dB,带宽为0.024 THz,y偏振光的消光比达到63.74 dB,带宽为0.02 THz,传输总损耗低至0.037 dB/cm.公差分析表明结构参数在±1%的偏差下,偏振分束器仍然可以保持较好的性能.A novel terahertz polarization beam splitter(PBS)with low loss and large bandwidth based on double core negative curvature fiber is designed.The device takes copolymers of cycloolefin as the substrate,and 12 circular tubes with embedded tubes are evenly distributed along the circumference.The fiber core is divided into two cores through two groups of circumscribed small clad tubes symmetrical up and down.The finite-difference time-domain(FDTD)method is used to analyze its guide mode properties.The effects of various structural parameters on its beam splitting characteristics are investigated in detail,and the extinction ratio(ER),bandwidth and transmission loss of the PBS are analyzed.The simulation results show that when the incident light frequency is 1THz and the beam splitter length is 6.224 cm,the ER of x-polarized light reaches 120.8 dB,the bandwidth with ER above 20 dB is 0.024 THz,the ER of y-polarized light reaches 63.74 dB,the bandwidth with ER above 20 dB is 0.02THz,and the total transmission loss is as low as 0.037 dB/cm.Tolerance analysis shows that the PBS can still maintain good performance under the±1%deviation of structural parameters.

关 键 词：太赫兹 偏振分束器 负曲率光纤 耦合模理论 

分 类 号：TN253[电子电信—物理电子学] O441.4[理学—电磁学]