基于逆设计的新型垂直耦合器

Inverse Design and Demonstration of Vertical Couplers

针对光栅垂直耦合器耦合效率低,仿真耗时长的问题,搭建了具有多层异质结构的逆设计仿真平台。将以逆设计功能为导向的思想及高性能计算的优势相结合,只需构建初始结构和设定目标功能,即可利用凸优化算法设计具有复杂多层异质结构的微纳光子器件。基于此平台,设计并实现了高性能垂直耦合器。此外,利用Al反射镜可极大地提高该垂直耦合器的耦合效率。仿真结果表明,该新型垂直耦合器在1550 nm处的耦合效率为88.42%(没有加Al反射镜时,耦合效率为32.45%),3 dB带宽为103 nm(1500~1603 nm)且具有良好的带宽特性和低损耗特性。

In view of the low coupling efficiency and long simulation time of vertical couplers,an inverse design simulation platform of multi-layer heterostructures is built.With the help of the function-oriented idea of the inverse design and the advantages of high-performance computing,micro/nano-photonic devices with complex multi-layer heterostructures can be generated automatically by convex optimization algorithms after the initial structures are built and the target functions are set.A high-performance vertical coupler based on this inverse design simulation platform is proposed in this paper.The coupling efficiency improves greatly after an Al mirror is integrated into the coupler.The simulation results show that the coupling efficiency of the coupler is 88.42%at 1550 nm wavelength(coupling efficiency is 32.45%without an Al mirror),and the coupler has a 3 dB bandwidth of 103 nm(1500--1603 nm)with good bandwidth and low loss characteristics.