基于混合表面等离子体弯曲波导的紧凑型宽带偏振分束转换器的设计研究  

Compact broadband plasmonic-assisted polarization splitter-rotator based on bent directional couplers

作　　者：张芳 徐培鹏 徐铁峰[1] ZHANG Fang;XU Peipeng;XU Tiefeng(Faculty of Electrical Engineering and Computer Science,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学信息科学与工程学院,浙江宁波315211

出　　处：《宁波大学学报（理工版）》2020年第3期45-49,共5页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：国家自然科学基金(61875099,61505092);浙江省自然科学基金(LY18F050005);宁波大学王宽诚幸福基金.

摘　　要：设计了一种宽带的基于混合表面等离子体弯曲波导的偏振分束转换器,使用有限元法计算硅波导、混合表面等离子体波导的模场分布和有效折射率,为器件建模仿真分析提供了依据.使用时域有限差分法优化器件结构,以获得最佳的性能参数.由于混合表面等离子体波导的双折射增强,设计获得的偏振分束转换器具有超小尺寸和宽带的工作特性.仿真结果表明:在1 550 nm的中心波长处消光比大于23 dB,插入损耗小于0.8 dB;在80 nm的带宽上,横磁偏振光转换为横电偏振光的偏振转换效率大于95%.We propose a plasmonic-assisted polarization splitter-rotator(PSR) based on bent directional couplers.The finite element method is used to calculate the mode field distribution and effective refractive index of silicon waveguides,as well as hybrid surface plasmon waveguides,all of which provide an important basis for device modeling and analysis.We simulate light propagation in the proposed device by a three-dimensional finite-difference time-domain method.With the enhanced birefringence resulting from the plasmonic-assisted asymmetry,the present PSR features ultra-compact size and broadband operation.Our simulation results show an extinction ratio greater than 23 dB and an insertion loss lower than 0.8 dB at the central wavelength of 1 550 nm.The TM-to-TE polarization conversion efficiency is improved by more than 95% over a bandwidth of 80 nm.

关 键 词：集成光学器件 偏振控制器件 表面等离子体激元 相位匹配 

分 类 号：TN256[电子电信—物理电子学]