基于伴随法逆向设计的硅基分模器  

Silicon Mode Splitter Obtained by Inverse Design Based on Adjoint Method

作　　者：陈涛[1] 毛思强 万洪丹[1] 汪静丽[1] 蒋卫锋 Chen Tao;Mao Siqiang;Wan Hongdan;Wang Jingli;Jiang Weifeng(College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China)

机构地区：[1]南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院,江苏南京210023

出　　处：《光学学报》2023年第23期165-172,共8页Acta Optica Sinica

基　　金：国家自然科学基金青年科学基金(11904178)。

摘　　要：基于伴随优化设计算法逆向设计了一种高集成度硅基分模器。通过优化设计得到横电模TE_(0)和TE_(1)双模分模器的尺寸仅为5.5μm×4μm,其可在不改变模阶数的情况下实现模式高效分离。理论结果显示:当输入TE_(0)模式时,中心波长处的插入损耗和串扰分别为0.14 dB和-23.8 dB;当输入TE_(1)模式时,插入损耗和串扰分别为0.48 dB和-22.45 dB;工作带宽覆盖150 nm时,TE_(0)和TE_(1)模式的插入损耗分别低于0.44 dB和1.16 dB。基于全矢量三维有限时域差分法分析了±15 nm制备容差,两种模式的插入损耗低于0.79 dB,串扰低于-18.37 dB。所提出的紧凑型硅基分模器可应用于片上模分复用系统,为大容量片上光通信和光互联提供可行器件。Objective Space division multiplexing(SDM)technology has emerged to break through the transportation capacity limitations.As an important technical route to achieve SDM,mode division multiplexing(MDM)technology features high information density,low transmission cost,and low energy consumption.According to our investigation and research findings,there are many in-depth studies and reports on the implementation of various components in MDM systems.However,there is little research on the mode splitter.In MDM systems,mode-sensitive components have selectivity for input and output waveguide modes,and mode splitting based on a traditional mode demultiplexer is difficult to meet the requirements.Therefore,employing a mode splitter that does not change the mode order is an important method to improve the flexibility of MDM systems.The silicon-based mode splitter is a key device for constructing an on-chip MDM system to realize flexible routing of different modes.We propose a compact silicon-based mode splitter based on an adjoint optimization design algorithm and adopt the 3D full-vectorial finite-difference time domain(3D-FV-FDTD)for simulation verification.The simulated results show that the performance of the designed mode splitter meets the design targets,such as small size,low insertion loss and crosstalk,and large bandwidth.Thus the splitter can be applied to on-chip MDM systems,providing a viable device for high-capacity on-chip optical communications and optical interconnects.Methods Traditional design depends on the researchers'experience to achieve design goals by optimizing structure parameters.By contrast,the inverse design method is a goal-oriented approach that utilizes inverse algorithms to design various structures,which could reduce design complexity and improve design efficiency.We leverage an inverse design method to optimize the structure.The whole design process is divided into five steps as shown in Fig.3,including initializing structure parameters,simulating and calculating gradient,binarization,de

关 键 词：集成光学 硅基光电子学 硅基分模器 逆向设计 伴随法 

分 类 号：TN252[电子电信—物理电子学] TN256